How to convert numbers into assigned letters?

[Kent_Pi]

I am looking for a way to assign a letter to a specific number digit.

Example:

Assigned letters for each numbers

And the number to be converted is 4563

The converted number should then look; HTYG

I am looking for a way to make this for days, but I couldn't find any way. Hopefully, someone could help me and give me some ideas. Thank you so much.

[#2]

@Kent_Pi 

Assuming you run Excel 2021 or 365 (you didn't mention...)

in B1:

=TEXTJOIN("",,
    XLOOKUP(--MID(A1,SEQUENCE(LEN(A1)),1), E$2:E$11, D$2:D$11)
)

(Range D2:E11 can be on a different sheet)