It’s possible to use “Admin menu access” add-on to check what user capability protects the selected plugin menu item:
– activate admin menu access add-on;
– open ‘administrator’ role at User Role Editor;
– click “Admin Menu” button;
– find menu items related to the “Forms” plugin.

It’s the “edit_posts” for “FM Email Verification” menu and “manage_options” for “Form Maker”, “Form Maker Addons” menus. Every item of the “Form Maker” submenu is protected by “manage_options” capability too.
The next step is create a role which has access to the WordPress back-end, start from a subscriber role, add to it “manage_options” user capability and block for it the unused menu items.
Look at the demo video.