Google access token missing in request in dialogflow but not on google test

hi, i wrote a google action skill in voiceflow with linked account in the google action console. on google test page i see the request (forwarded to dialogflow webhook) with the access_token inside. but on dialogflow, the access_token variable still blank.
how can i get the access_token variable attached by google or access to complete request received by dialogflow webhook?

thanks in advance.