Error in logfiles

My Nextcloud logfile shows the following error repeatedly:

[PHP] Error: You are using a fallback implementation of the intl extension. Installing the native one is highly recommended instead. at /var/www/html/nextcloud/3rdparty/patchwork/utf8/src/Patchwork/Utf8/Bootup/intl.php#18

Can anybody tell me what I need to do to resolve it, thanks.

As written in the error message, Install and configure the php-intl extension :wink:
https://help.nextcloud.com/search?q=php-intl
https://docs.nextcloud.com/server/19/admin_manual/installation/source_installation.html?highlight=php%20intl#prerequisites-for-manual-installation