Including a toe-kick might have been a better way to build these cabinets, but we can't see exactly what/where this is.

Can you show a photo from further back? Is this the back of a peninsula?

It looks like veneer over pressboard, and the veneer has water damage plus one small missing area? It’s also not a very noticeable location, down at foot level. I would very lightly sand the damaged veneer to smooth it out a bit, use some wood filler to fill the missing part, brush on some stain in a color that matches the existing as much as possible, and call it good. Will it be “good”, no, but it should be improved enough that you can forget about it.

That's a $500 job for pro. I concur with John Liu

You could possibly re-veneer the area in red, and use a stain marker to color correct the rest. In the re-veneered part the grain will not be identical, but it’s a spot where you might not notice that.

If the area is damaged from constant water exposure, you’ve got a few practical options. First, let everything dry out completely and assess whether it’s just surface staining or actual rot. For minor damage, sanding and sealing the area with a waterproof sealant or exterior-grade paint can help prevent future issues. If the material is swollen or rotted, replacing that section with something water-resistant like tile, vinyl plank, or a rubber/waterproof mat designed for pet bowls is usually the best fix. Going forward, using a splash-proof or elevated water bowl with a tray underneath can help keep the area protected.