Keyboard with shifting notes to go higher and lower?

I'm looking for a cheap keyboard etc to play all pitches of the voice. I made the mistake and got a notebook with 49 keys but unfortunately without a shift of the tones is possible, i.e. A key with which one can go lower and higher to shift the tones, so to speak. Do you have any good recommendations?

Have a look at the reviews or ask the manufacturer if the device can transpose / shift octave.

Can't.

Also doesn't answer my question, do you have a product recommendation?

But you can look for keyboards and then ask the manufacturer / provider

That doesn't help me here, the answer isn't helpful.

Akai MPK 261.