Answer by Kamil Maciorowski for xterm ignores button remapping command

• NumpadSubtract does not work for me in Kubuntu 24.04 LTS. Sole KP_Subtract is also wrong. The right string is <KeyPress>KP_Subtract.
• string(0x1b) string(0x5b) string(0x41) generates what ↑ generates. I started xxd, pressed F4, Ctrl+D, Ctrl+D and got 1b4f 53.

With this knowledge I created a command that works for me:

xterm -xrm 'XTerm.VT100.translations: #override <KeyPress>KP_Subtract: string(0x1b) string(0x4f) string(0x53)'