Permissions needed to create forms

Plumsail Forms data is stored in the pages library. Members on our sites have only read permissions to this library to prevent them from changing the site. So far so good because this means they also cannot mess up the Plumsail forms.
Each site has one or more key users who have contribute permissions on the pages library. On a site where Plumsail hasn’t been used before these key users cannot save new forms. First use of Plumsail on a site seems to require site collection admin permissions. Is this a correct assumption?
With all subsequent use of Plumsail on the site, contribute seems to be enough.

My question is, what permissions levels are needed on which Site elements to work with Plumsail forms while still having the forms being secured from editting by normal members.

Hello @Pieter,

Welcome to Plumsail Community!

Plumsail Forms requires scripting capabilities to be enabled on the site collection level.

When a user saves the form to a new site, you need to make sure that the scripting capabilities are enabled. Otherwise, you should enable them manually following the instructions.

If scripting capabilities are enabled, users with contribute permission to Site Pages library can design forms.