Hi, so recently my steam account was hacked and now i just added some money to my gameflip wallet and when i tried to buy something on steam it says bad trade url and when i check turns out my gameflip account is still connected to the old account. is there a way to connect another account?
https://forum.gameflip.com/t/change-my-steam-account/11753/2
This from February 2018 so things may changed. Lets wait into @DunnBiscuit answer your question.
Lucy 
but the thing is i just added money to the account 
This is more recent
This from December 2018
(I think Steam account are locked to your Gameflip account)
Regardless if you can’t be change you can always do Coordinated Transfers with a Seller.
Lucy
can you tell me how to do a coordinated transfer? thanks in advance
Coordinated Transfers
This option is designed for a more open delivery in which the Seller and Buyer will need to work together to complete the transaction.
If you go to the item you like you need to look at the Delivery Method and see if it said Coordinated Transfers.
Example
This user kind of had the same issues as you and they found a seller and got items from them.
(Please click and read this post to fully understand what I meant. I’m not sure what steam items you’re looking for so this Seller may be no good for you.)
Lucy
If he just wants to buy things can’t he simply change his trade link under settings ? If not that’s a terrible design.