How to login as another user on selfhosted core?

How does a user login? I have 2 users on the self hosted version:

me> sqlite3 landing.db
sqlite> .mode box
sqlite> select * from logins;

┌────┬─────────┬────────────────────────┬────────────────────────┐
│ id │ user_id │         email          │     display_email      │
├────┼─────────┼────────────────────────┼────────────────────────┤
│ 6  │ 6       │ services@example.com   │ services@example.com   │
│ 8  │ 8       │ vinnland@example.com   │ vinnland@example.com   │
└────┴─────────┴────────────────────────┴────────────────────────┘

The user vinnland@example.com is an editor of one of my documents.

How do I get someone else to login as vinnland@example.com?

NOTE: services@example.com is the GRIST_DEFAULT_EMAIL.