This solution worked for me.
When my previous url was: "/mod/lti/services.php/5/lineitems/8/lineitem?type_id=3/scores"...this was the error I was getting:
{"status"=>400, "reason"=>"No handler found for /5/lineitems/8/lineitem application/vnd.ims.lis.v1.score+json", "request"=>{"method"=>"POST", "url"=>"/mod/lti/services.php/5/lineitems/8/lineitem?type_id=3%2Fscores", "accept"=>"*/*", "contentType"=>"application/vnd.ims.lis.v1.score+json"}}Then I changed the url to "/mod/lti/services.php/5/lineitems/8/lineitem/scores?type_id=3" and everything works fine now.
