by Urvesh Nagda.
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.