I had accepted an offer from company A for amount x. After that, I have received another offer from company B for amount x+3. But I am keen to join company A.

Now, can I go back to company A and let them know about offer from company B? Is there any possibility they might match the offer? Or they might take it negatively and reject the current offer?

Normally, we don't negotiate after the offer acceptance but have you done it, how did it go?