Solution:
For the role in which you want to schedule a publication,
Go to Settings > Users & Roles > Roles
uncheck → This role is only allowed to recommend a review decision and will require an authorised editor to record a final decision.
Again this will only effect from current submission.
For the submission, you are facing the issue
“You don’t currently have access to that stage of the workflow.”
go to workflow > select the participant > and click edit.
uncheck → This role is only allowed to recommend a review decision and will require an authorised editor to record a final decision.
Now try to schedule your publication!