What should be the rights to folders? What kind of mistake?

What kind of mistake? You do not have permission to create or upload files to this folder.

What rights should there be to these folders?
• Some directories are not owned by the account under which the web server process is running. This usually happens during a manual installation. Check the permissions on the following application directories:
o /home/a/alexbemo//public_html/apps/accessibility
o /home/a/alexbemo/
/public_html/apps/activity
o /home/a/alexbemo//public_html/apps/admin_audit
o /home/a/alexbemo/
/public_html/apps/announcementcenter
o /home/a/alexbemo//public_html/apps/bruteforcesettings
o /home/a/alexbemo/
/public_html/apps/calendar
o /home/a/alexbemo//public_html/apps/circles
o /home/a/alexbemo/
/public_html/apps/cloud_federation_api
o /home/a/alexbemo//public_html/apps/comments
o /home/a/alexbemo/
/public_html/apps/contacts
o /home/a/alexbemo//public_html/apps/contactsinteraction
o /home/a/alexbemo/
/public_html/apps/dashboard
o /home/a/alexbemo//public_html/apps/dav
o /home/a/alexbemo/
/public_html/apps/deck
o /home/a/alexbemo//public_html/apps/encryption
o /home/a/alexbemo/
/public_html/apps/external
o /home/a/alexbemo//public_html/apps/federatedfilesharing
o /home/a/alexbemo/
/public_html/apps/federation
o /home/a/alexbemo//public_html/apps/files
o /home/a/alexbemo/
/public_html/apps/files_accesscontrol
o /home/a/alexbemo//public_html/apps/files_automatedtagging
o /home/a/alexbemo/
/public_html/apps/files_external
o /home/a/alexbemo//public_html/apps/files_pdfviewer
o /home/a/alexbemo/
/public_html/apps/files_retention
o /home/a/alexbemo//public_html/apps/files_rightclick
o /home/a/alexbemo/
/public_html/apps/files_sharing
o /home/a/alexbemo//public_html/apps/files_trashbin
o /home/a/alexbemo/
/public_html/apps/files_versions
o /home/a/alexbemo//public_html/apps/files_videoplayer
o /home/a/alexbemo/
/public_html/apps/firstrunwizard
o /home/a/alexbemo//public_html/apps/logreader
o /home/a/alexbemo/
/public_html/apps/lookup_server_connector
o /home/a/alexbemo//public_html/apps/mail
o /home/a/alexbemo/
/public_html/apps/nextcloud_announcements
o /home/a/alexbemo//public_html/apps/notifications
o /home/a/alexbemo/
/public_html/apps/oauth2
o /home/a/alexbemo//public_html/apps/password_policy
o /home/a/alexbemo/
/public_html/apps/photos
o /home/a/alexbemo//public_html/apps/privacy
o /home/a/alexbemo/
/public_html/apps/provisioning_api
o /home/a/alexbemo//public_html/apps/recommendations
o /home/a/alexbemo/
/public_html/apps/registration
o /home/a/alexbemo//public_html/apps/richdocuments
o /home/a/alexbemo/
/public_html/apps/richdocumentscode
o /home/a/alexbemo//public_html/apps/serverinfo
o /home/a/alexbemo/
/public_html/apps/settings
o /home/a/alexbemo//public_html/apps/sharebymail
o /home/a/alexbemo/
/public_html/apps/socialsharing_email
o /home/a/alexbemo//public_html/apps/spreed
o /home/a/alexbemo/
/public_html/apps/support
o /home/a/alexbemo//public_html/apps/survey_client
o /home/a/alexbemo/
/public_html/apps/systemtags
o /home/a/alexbemo//public_html/apps/text
o /home/a/alexbemo/
/public_html/apps/theming
o /home/a/alexbemo//public_html/apps/twofactor_backupcodes
o /home/a/alexbemo/
/public_html/apps/updatenotification
o /home/a/alexbemo//public_html/apps/user_ldap
o /home/a/alexbemo/
/public_html/apps/user_saml
o /home/a/alexbemo//public_html/apps/user_status
o /home/a/alexbemo/
/public_html/apps/viewer
o /home/a/alexbemo//public_html/apps/weather_status
o /home/a/alexbemo/
/public_html/apps/workflowengine

Unfortunately you haven’t provided any valuable information about how you have installed Nextcloud and how you expect Nextcloud to access the folder in the users home directory. Ususally that path is outside of the Nextcloud data directory and cannot be accessed by default because as reported in the message the web server process is unable to access it.

Web installer via hosting

there are rights to the data folder

which folder still needs to be granted access?

The doc root and the data folder and all their contents need to be owned by the web server’s user and group and never changed.

It could, of course, also be something weird that your web host is doing.