That up front fees are there when you buy a leasehold flat?

Hi, me and my partner are looking to move in a few mnths time and are going through out options. We have been looking into leasehold flats are are not fully clear on hoe it works. We understand that when you own a leasehols you own the interior of the property but not the exterior of the flat and that you have to pay the rent and ground rent. What we are struggling to understand though is do you get a mortgage on a leasehold or to you just pay a monthly rent like you do when renting a property? Also what upfront fees are there to pay before moving in? Do you need to pay a deposit? Any fees for credit checks or anything? Or any thing else on top of these?

Read more: That up front fees are there when you buy a leasehold flat?