Sunken areas of floor; what type of self levelling compound?

Getting Karndean Van Gogh Rigid Core LVT on concrete floor.
Had central heating pipes dug into the hall floor 22 years ago approximately. One area has subsequently sunk down up to 1cm, other parts are a bit cracked and one bit has a lump of cement?
Most of it is fine, with just some cracks here and there.
Would it just need self levelling in the worst areas and with what?
What would the cracks need to be filled with if at all?
We can feel some heat from the central heating pipes through the concrete in some areas, would this affect the Karndean?
Hoping we don’t need to screed the whole hallway….

Any advice greatly appreciated
Tried to post photo but it said file too large for server

 

Try using Tapatalk to post the pictures.
Yes floor needs to flat to have a LVT click.

 

If you can feel the heat then its over 27 degrees which i think could cause problems. Rigid core is one of the better products for dealing with heat so you may be ok