Consider that the "main menu" is at top right corner of the stackedit.io page.
In the first step, log in with a Google account
to synchronize all data.
Add via this link.
Redirect URI
type https://stackedit.io/oauth2/callback
;Confidencial
;api
option;Click on main menu
(StackEdit icon) -> Accounts
-> Add a GitLab account
.
GitLab URL
type https://gitlab.com/oauth/applications/<application-id-in-the-url>
;Application ID
paste the Application ID
copied from https://gitlab.com/oauth/applications/<application-id-in-the-url>
;Ok
.main menu
-> Synchronize
-> Save on GitLab
;Ok
.