Hi Nouman, Thanks for posting your concern.
It appears that the service account and installed / web application are both configured in your PHP client library. This is the possible reason why the issue occurred as there is a validation in PHP client library (provided below) that when service account and installed / web application are both configured, it will throw the said error. if (($this->jsonKeyFilePath !== null || $this->scopes !== null) && ($this->clientId !== null || $this->clientSecret !== null || $this->refreshToken !== null)) { throw new InvalidArgumentException( 'Cannot have both service account ' . 'flow and installed/web application flow credential values set.' ); } With this, since you want to configure the installed application, then you may undo the configuration of service account. Let me know how it goes after trying the provided suggestion. Regards, Ernie John Blanca Tacata Google Ads API Team ref:_00D1U1174p._5004Q28mwoV:ref -- -- =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ Also find us on our blog: https://googleadsdeveloper.blogspot.com/ =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~ You received this message because you are subscribed to the Google Groups "AdWords API and Google Ads API Forum" group. To post to this group, send email to adwords-api@googlegroups.com To unsubscribe from this group, send email to adwords-api+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/adwords-api?hl=en --- You received this message because you are subscribed to the Google Groups "AdWords API and Google Ads API Forum" group. To unsubscribe from this group and stop receiving emails from it, send an email to adwords-api+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/adwords-api/7BKXA000000000000000000000000000000000000000000000QKYOO700lsQ8ms6HQYCYpOqfotO23Q%40sfdc.net.