Can you please explain more how to do that?
If I understood you currently, you suggest me to pay for other service to help my transaction to be verified fast?
Sure... If you want to pay a pool, I recommend
https://pool.viabtc.com/tools/txaccelerator/A cpfp is using the unconfirmed unspent output funding your address in a new transaction that has a fee to cover both the stuck and the cpfp tx. The electrum wallet actually has a cpfp wizard, but if you want to use it, you"LL have to use electrum to begin with.. if you didn't use electrum to create your withdrawal address, it's a big hassle to convert your wallet to electrum.
But anyways, if you're the seller, and you didn't send the goods yet, I would just wait until the tx is confirmed. You're holding all the cards here...