yes add/create a token by:
home > site administration > plugins > web services > manage tokens
also make sure you allow check field at:
Site administration > Plugins > Web services > External services, edit "Moodle Mobile additional features" and check the "Enabled" field, then save changes.
Then go to Site administration > Users > Permissions > Define roles, edit the Authenticated user role and allow the capability moodle/webservice:createtoken.