Lost external hard drive files due to "partition"?

Hello everyone,
Earlier today, I tried to transfer photos from my sister’s mac to an external hard drive. After figuring out it was not working because of the files formats was different, I tried to reformat the external hard drive by clicking on “partition”. Afterwards, I clicked on the AFPS format and clicked to reformat. As a result, my external hard drive has been entirely wiped of its 800gb data which I really need to recover.
Two obstacles I’ve encountered so far are the fact that the external hard drive is now encrypted and I’m unable to see it on my window laptop.
Secondly, when I try to recover files through the mac using softwares, it cost ridiculous amounts.
Are there any free ways to recover files in this situation?
Thank in advance!