Please help me find a product for my 3 mth old?

Hopefully someone can help me,

I have a 3 month old who's quite big and very strong, I have a corner sofa that when I use to leave the room to do his bottles I would leave him right in the corner so he wouldn't fall.

He's started throwing himself around so I can't do that anymore but he's almost too big for his bouncing chair (picture) and I'm scared he's going to launch himself up out of his sit me up bear as hes so strong with his legs.

What product can I buy to safely put him while I leave the room or go to the toilet as I don't want him to get hurt.