no tmi-sent-ts is the server timestamp for the message
you want the id
As per this JSON-ified example
{
"command":"",
"room":"#cohhcarnage",
"nick":"barrycarlyon",
"target":"",
"body":"A test messge",
"tags":"badge-info=subscriber/83;badges=moderator/1,subscriber/78,ambassador/1;client-nonce=383a7d808766b10a460a9997fdab7a46;color=#033700;display-name=BarryCarlyon;emotes=;flags=;id=3b010d43-af3f-4f58-a8e6-11128e8fa4c6;mod=1;room-id=26610234;subscriber=1;tmi-sent-ts=1607696996823;turbo=0;user-id=15185913;user-type=mod"
}
If you look in the tags you will see an id of 3b010d43-af3f-4f58-a8e6-11128e8fa4c6