At the moment it is not possible to have another account to access the Catalog Maker, only Shopify users can provide Collaborator access to external people so that they only have access to the applications.
But we have an alternative option to give access to the app to a second person, you must follow the following steps:
To give access to another user with the same email but with a different password.
In order to do that you must do the following:
-You must copy the email that you have associated with your account.
-You must put the email and select that you have forgotten the password (with this step you can create a new password)
-When you have done the whole process of adding a new password, you can provide the information to the person who will have access.