My cooler doesn't fit onto my motherboard

[tawdry jay]

Hi, I just got my new motherboard.
An ASRock Steel Legend Z790

The problem is my old shitty cooler doesn't fit. It collides with the heatsink at the top.

I'm only getting a new cooler next week.

Can I safely use the motherboard with the heatsink removed ?
(and then put it back on once I got a new cooler)

or should I use my old motherboard for now and only use the new one once I got a new cooler?

I know the cooler has terrible contact with the CPU
it's pretty bad
but it works for now