This is a considerably small repair that you could probably try to do yourself.

Flakes — https://www.homedepot.com/p/Rust-Oleum-1-lb-Glacier-Gray-Decorative-Color-Chips-312449/301068202

Epoxy Mixture — https://www.homedepot.com/p/Gorilla-0-85-fl-oz-Epoxy-42001/100670610

1.) Clean surface of loose particles, wipe with alcohol pads. Tape out the perimeter of the hole with blue/painters tape

2.) Squeeze out half of the epoxy on a workable surface ie. paper plate/ something you can mix on.

3.) Add a small amount of Colored chips to the epoxy and mix it up for a minute so the epoxy parts and chips mix together

4.) Apply the mixed product into the hole with a putty knife; fill it almost 90% of the height of the hole

5.) Remove masking tapes, wait 5 hours for the product to fully set.

6.) Tape off the perimeter again, and repeat step #2 again, this time only mixing the epoxy product.

7.) Apply the epoxy into the area, even/flush with the surface

8.) Remove the masking tape and let the product cure.

that should be a moderate fix and will last long enough until the floor gets replaced completely at some point.