No me funciona nextcloud¿alguien me puede ayudar?

no funciona me sale un error

Al introducir la direccion me sale el siguiente mensaje.

Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

el log pone lo siguiente:

[Sat May 30 00:00:02.810259 2020] [mpm_prefork:notice] [pid 5173] AH00163: Apache/2.4.38 (Raspbian) configured – resuming normal operations
[Sat May 30 00:00:02.810288 2020] [core:notice] [pid 5173] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 00:53:13.399023 2020] [mpm_prefork:notice] [pid 5173] AH00169: caught SIGTERM, shutting down
[Sat May 30 00:53:39.012327 2020] [mpm_prefork:notice] [pid 966] AH00163: Apache/2.4.38 (Raspbian) configured – resuming normal operations
[Sat May 30 00:53:39.012529 2020] [core:notice] [pid 966] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 00:53:46.688446 2020] [php7:warn] [pid 989] [client 192.168.1.132:53248] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63
[Sat May 30 01:07:07.853094 2020] [mpm_prefork:notice] [pid 966] AH00169: caught SIGTERM, shutting down
[Sat May 30 01:07:08.205508 2020] [mpm_prefork:notice] [pid 11732] AH00163: Apache/2.4.38 (Raspbian) configured – resuming normal operations
[Sat May 30 01:07:08.205635 2020] [core:notice] [pid 11732] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 01:23:54.435790 2020] [mpm_prefork:notice] [pid 11732] AH00169: caught SIGTERM, shutting down
[Sat May 30 01:23:54.760807 2020] [mpm_prefork:notice] [pid 795] AH00163: Apache/2.4.38 (Raspbian) configured – resuming normal operations
[Sat May 30 01:23:54.760947 2020] [core:notice] [pid 795] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 01:31:37.221170 2020] [mpm_prefork:notice] [pid 970] AH00163: Apache/2.4.38 (Raspbian) configured – resuming normal operations
[Sat May 30 01:31:37.221339 2020] [core:notice] [pid 970] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 01:37:47.786798 2020] [php7:warn] [pid 992] [client 192.168.1.132:53568] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63
[Sat May 30 01:43:52.892163 2020] [php7:warn] [pid 994] [client 192.168.1.132:53603] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63
[Sat May 30 01:45:10.959648 2020] [mpm_prefork:notice] [pid 970] AH00169: caught SIGTERM, shutting down
[Sat May 30 01:45:11.287596 2020] [mpm_prefork:notice] [pid 12897] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured – resuming normal operations
[Sat May 30 01:45:11.287749 2020] [core:notice] [pid 12897] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 01:45:48.581212 2020] [php7:warn] [pid 12898] [client 192.168.1.132:53606] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63
[Sat May 30 01:46:49.203752 2020] [php7:warn] [pid 12899] [client 192.168.1.132:53609] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63
[Sat May 30 01:47:04.787813 2020] [php7:warn] [pid 12900] [client 192.168.1.132:53611] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63, referer: http://192.168.1.158/nextcloud/
[Sat May 30 01:51:42.464842 2020] [mpm_prefork:notice] [pid 971] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured – resuming normal operations
[Sat May 30 01:51:42.464994 2020] [core:notice] [pid 971] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 01:57:15.814887 2020] [mpm_prefork:notice] [pid 971] AH00169: caught SIGTERM, shutting down
[Sat May 30 01:57:16.179622 2020] [mpm_prefork:notice] [pid 6282] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured – resuming normal operations
[Sat May 30 01:57:16.179768 2020] [core:notice] [pid 6282] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 02:03:18.020807 2020] [mpm_prefork:notice] [pid 6282] AH00169: caught SIGTERM, shutting down
[Sat May 30 02:03:18.355797 2020] [mpm_prefork:notice] [pid 11453] AH00163: Apache/2.4.38 (Raspbian) OpenSSL/1.1.1d configured – resuming normal operations
[Sat May 30 02:03:18.355931 2020] [core:notice] [pid 11453] AH00094: Command line: ‘/usr/sbin/apache2’
[Sat May 30 02:07:13.291732 2020] [php7:warn] [pid 11458] [client 192.168.1.132:53737] PHP Warning: touch(): Unable to create file /var/www/html/nextcloud/data/nextcloud.log because Permission denied in /var/www/html/nextcloud/lib/private/Log/File.php on line 63

Creo que es algo de permisos pero no se como sulucionarlo
por favor ayuda