def _get_sessionless_launch_url(self, context, context_id, tool_id):
url = context.format(context_id) + "<STR_LIT>"<EOL>params = {"<STR_LIT:id>": tool_id}<EOL>return self._get_resource(url, params)<EOL>
Get a sessionless launch url for an external tool.

https://canvas.instructure.com/doc/api/external_tools.html#method.external_tools.generate_sessionless_launch