In amp-update-cache sample we are getting amp_ts=undefined error.

[syedimran22]

Desc: Invalid or missing 'amp_ts' parameter for the sample url https://limitless-tundra-65881.herokuapp.com/amp-access/sample/0 of amp-update-cache

screenshot:
https://user-images.githubusercontent.com/41104393/78786630-b11a5580-79c6-11ea-8bf9-aa2d43b2eb27.png