Google App Script not evaluating anchor tag properly

[Mohammed Imtiyaz]

Hi!, I'm trying to append the authorization URL generated using :

googlesamples/apps-script-oauth2 library. 

But, the HTML is evaluated like this :

'<a href="#ZautoescZ-caja-guest-0___" target="_blank">Authorize</a>'.

When i print this authorization URL it shows the desired result i.e. appending all the required parameters for OAuth authorization URL. 

I don't understand what's causing this problem, any help would be appreciated.