Learn Hardcore Ukrainian: Переказ коштів можна скасувати.

Because коштів is in the genitive plural, and that is the normal form after a noun like переказ when you mean a transfer of funds / money transfer.

So:

переказ = transfer, remittance
кошти = funds, money
переказ коштів = transfer of funds

This is very similar to English transfer of funds, where of funds depends on transfer.

Also, кошти is usually used only in the plural, so its dictionary form is кошти, and the genitive plural is коштів.

What does можна do in this sentence?

Можна means it is possible / one may / can. It is a very common Ukrainian impersonal word used with an infinitive.

So:

можна скасувати = can be canceled / it is possible to cancel

This construction does not need a personal subject like I, you, or they. It is just a general statement about possibility.

Examples:

Це можна зробити. = This can be done.
Квиток можна повернути. = The ticket can be returned.

Why is скасувати an infinitive?