add contact to group

I created a group. Now I can't add additional contacts to that group in the same way I added them in the first place. Here is the google search: Steps to Add a Contact to a Group (Contact List) IT DOES NOT WORK!

1. Open Contacts: Click on the Contacts tab in your Tuta account.
2. Locate Contact Lists: In the contacts section, look for the section named Contact lists.
3. Edit the List: Select the existing contact list you want to add the person to, or create a new one.
4. Add Person: Select the contact(s) from your main contact list to be included in the group/list, or directly add the email address when creating the list.
5. Save: Ensure you save the changes to the contact list. [1, 2, 3, 4, 5]

Does anyone know how to do this please?