Portal accounts have various level of permissions. Not all account types can publish all service types.
You must be an administrator to publish web tools. If using an ArcGIS Enterprise administrator account, ensure it is also an ArcGIS Server administrator as well.
Some tools check the permissions of the active portal account. Reference the specific geoprocessing tool help for requirements.
Talk to your server/portal administrator for another account or to elevate the permissions of your current account.