User1: Project Administrators -
You must have the permission Create Repository to publish code as wiki. By default, this permission is set for members of the Project Administrators group.
User2: Contributors -
Anyone who is a member of the Contributors security group can add or edit wiki pages.
Anyone with access to the team project, including stakeholders, can view the wiki.
Reference:
https://docs.microsoft.com/en-us/azure/devops/project/wiki/wiki-create-repo