What do you think of Trump\s claim that Biden was forced to resign?

In a way, Trump is right.  Biden, after meeting with those in his party and in his circle of advisors, realized at some point that if he continued running, the Democrats would not win and, for the good of the country, backed out.  I believe he is to be commended for making that very difficult decision.

I believe Biden was encouraged or even pressured to drop out, but forced is a pretty strong word. If Biden were truly incapable of serving out his term, due to physical or cognition issues, I strongly believe he would received the same pressure to resign the presidency.

That said, there were most likely multiple factors in his decision to drop out. The pressure from his party, certainly, but also the fact that Biden knows his speaking and campaigning skills are not his strong suit which could cost the election and affect downballot races. He prefers to work behind the scenes to get things done, which is one reason he doesn't get the credit he deserves Finally, his bout with Covid may have given him a reminder that he faces health risks that will keep increasing as he ages. It's over a year since I had my only case of Covid and I don't feel that I have gotten or will get back to pre-Covid levels of stamina and energy. Biden is a lot older than I am and this was his second case. Each bout of Covid has increasing risks for the elderly.

I think in addition to that, he wanted to focus on doing his job and not on campaigning. It's hard to give up power when you still feel you can accomplish more but he had the strength of character to do it. And yes, I  think he knew Kamala Harris was ready.

Trump is Trump and I never know whether he is saying what believes or what he wants others to believe. 

He was absolutely forced out.  I don't know exactly what they used but there is plenty of ammo to use against Biden and Family.  

Biden went from I am running and that is after the debate.  To I'm out and I endorse Harris in a letter.  Even Pelsoi said the letter did not sound like Biden. 

I also believe this is why Biden endorsed Harris.   It was a last twist of the knife to those who forced him out. They did not want Harris.  (She got less than 1000 votes in the 2020 primary) They wanted an open convention.   And who knows the convention has not happened yet, they may still get it.