The TMS template is based on hard coded values, phrases and sections. It will not work with if/else statements like python logic. The hardcoded values can be called in the template manually under the applicable section, as well as in html based booking invite template you can manually create links for things like logos, dtmf etc.
Look here on pg 241: https://www.cisco.com/c/dam/en/us/td/docs/telepresence/infrastructure/tms/admin_guide/Cisco-TMS-Admin-Guide-15-8.pdf
There is already a section for Webex Conference information in addition to the normal sip video address.
<SECTION:WEBCONF_PASSWORD>{WEB_CONFERENCE_PASSWORD} - <VAL:WEBCONF_PASSWORD>
</SECTION:WEBCONF_PASSWORD><SECTION:WEBCONF_HIDDEN_PASSWORD>{WEB_CONFERENCE_PASSWORD} - {CONTACT_HOST}
</SECTION:WEBCONF_HIDDEN_PASSWORD>{WEB_CONFERENCE_ID} - <VAL:WEBCONF_ID>
</SECTION:MEETING_WEBCONF_DETAILS><SECTION:TELEPRESENCE>______________________________________________________________________
