To integrate with IFTTT, follow these instructions: https://www.home-assistant.io/integrations/ifttt/#sending-events-from-ifttt-to-home-assistant
For everything else, looks like you’re having trouble because the “legacy api password” is deprecated. You’ll have to use “long lived access tokens” and these are not stored in the URL but in the body of the http call. Example here: Tasker & Long Lived Access Tokens
It’s not easy, but good luck.