Ok.
You can get the plastic/rubber thing you posted.
but you will still need to seal round it with silicon sealer.
the DIY stores will have a rubber bung/boss that will fit the pipe and the opening in the floor but they are expensive and will most likely still leak a little.
I doubt the pipe in the floor is blocked as you had no issue before.
it's the volume of water trying to go down the pipe.
This is what I do, have done in several Thai style homes.
forget any insert, just buy a good quality, ( not a cheap one ) clear silicone sealer
and silicone the pipe straight in the floor. let it set 24 hours.
clean and dry and key , all surfaces first.
cut the pipe to the correct length, leaving enough to pull the machine out if needed in the future.
make sure you push a good 2 inch of the pipe in the floor covered in silicon, and smooth a lot round the top when finished.
yes it a bit messy, but will last a few years.
easy to redo, easy to get out if needed.
Good luck.