[Pharo-users] adding credentials to a repo via a playground script

Hi, is it possible to add credentials to an existing repo via a script? I've tried something like ~~~~~~~~~~~~~~~~~~~~~~~~~ |repo| repo := MCSmalltalkhubRepository allInstances detect: [ :each | each location includesSubstring: 'Pharo50Inbox' ]. repo user: 'peteruhnak'; password: '******' ~~~~~~~~~~~~~~~~~~~~~~~~~~ but it has no effect. Thanks, Peter