Simply declare each private ssh keys in a %HOME%/.ssh/config file:
```
Host gitlabuser1
User git
Hostname {hostname}
PreferredAuthentications publickey
IdentityFile C:/Users/{username}/.ssh/id_rsa1
Host gitlabuser2
User git
Hostname {hostname}
PreferredAuthentications publickey
IdentityFile C:/Users/{username}/.ssh/id_rsa2
```
That supposes your set of ssh keys are:
```
%HOME%/.ssh/id_rsa1 ; %HOME%/.ssh/id_rsa1.pub
%HOME%/.ssh/id_rsa2 ; %HOME%/.ssh/id_rsa2.pub
```
You can then use the urls for clone/push/pull:
```
gitlabuser1:yourRepo1
gitlabuser2:yourRepo2
```
via https://stackoverflow.com/questions/30320458/how-to-set-up-two-ssh-keys-for-two-gitlab-accounts-and-push-pull-by-using-tortoi