You have your Safevia Forms plugin already installed to WordPress, you created key (in Admin Panel, under the section Safevia Forms -> Manage Keys). You want to insert a new Safevia Form with the default (Gutenberg) editor.
To create a Form with Gutenberg, all you need is to find a “Safevia Forms” block and place it into your page.
Very first step of the configuration is to name it and select the key, to encrypt all the form values.
Add and configure Form fields. Safevia has following attributes: