Facts First: The tweet is inaccurate in multiple ways.
1) Trump would lose his post-presidency pension only if both the House voted to impeach him and then the Senate voted to remove him from office; impeachment itself, without removal, would not result in Trump being denied any benefits.
2) The law makes clear that presidents who have lifetime Secret Service protection never get a $1 million travel allowance.
3) It is unclear that Trump would lose lifetime Secret Service protection even if the Senate voted to remove him and prohibit him from running.
4) Even a Senate vote to remove Trump would not prohibit him from running in 2024; for the Senate to ban him from the presidency, it would have to hold an additional vote on this question.