I made it work, You need to go to Plugins > Plugin editorDon't know. So far I haven't heard from any of the experts here.

then in the top right corner , in the drop down menu, select > Wpforms and hit Select

then a code editor will open and you need to got to line number 39 , it will say
update_option( 'wpforms_license', [
'type' => 'basic',
'key' => 'valid',
'is_expired' => false,
'is_disabled' => false,
'is_invalid' => false,
] );
you need to replace the 'basic' with 'pro' as shown in picture below

after doing this, you need to click on "update file" in the bottom left.
It works for me, for Addons, you need to update addon.zip throuh plugin installer and activate it.
Done