HEX only for entering card datd?

Can anyone help with understanding how to work with entering card numbers into the flipper manually when the only way to do this is with a HEX editor? All the cards I work with are either decimal numbers like 150988773940, or their BINARY equivalent. Nothing I work with uses HEX? is this as simple as just converting the decimal number to a HEX value? is it right to left, or left to right?

Flipper’s hex is typically the dumbest possible representation of wire format, and/or clone of what another tool did before.
Cards usually have FC/CN (Facility code/Card number) written on it.
Details may depend, e.g. it may or may not be full information necessary.

If your Flipper can;t scan the card, it is likely an unsupported type and you won’t gain anything with manual input. If you are working with photo, scanning another card from the same system would be helpful.