Can't finish nextcloud install on ubuntu 20.14

Hi, have searched here for similar topics but no help.
I have set up ubuntu 20.4 server edition and installed the LAMP stack with no problems.
I installed nextcloud from snap (snap, snapd version 2.45.2 series 16) (nextcloud 19.0.1snap2)

Having Googled around I understand that I need to finish the nextcloud installation (before I can add a user) thus:

frderek@badbury:~/snap/nextcloud/22400$ sudo nextcloud.occ maintenance:install
What is the password you like to use for the admin account ?
Can’t create or write into the data directory /snap/nextcloud/22400/htdocs/data

As you can see, it doesn’t work. /htdocs doesn’t exist under /22400

Googling comes up with no solution to this specific problem and the nextcloud forums just say “I wouldn’t use snap, here’s how to do it manually”!

SOMEONE must have solved this? help please as I really do want to use snap to keep everything up-to-date.