Hello my dude. Have you already purchased replacements?

As it happens, I have an entire set of k70 rgb caps I’m not using after I killed my old keyboard with a cup of coffee.

There are a lot of vendors that sell full keycap sets. Here is one: https://mechanicalkeyboards.com/

There are various types of keycaps. They can all be one size, they can be different heights on each row, they can have letters printed on ($) or they can be several layers of different colored plastic with the letters being part of the molding process ($$$).

Welcome to the mechanical keyboard experience!

Any MX-compatible keycaps will fit on the switch stems.

Keycap widths are measured in units: you want 1u caps for Escape, and the cursor key; 1.5u for Tab, 1.25u for the other three keys on the lower row.

Ideally you want replacements to match the "profile" of the other keys so that sizes and shapes match. I think this board uses OEM profile, but I'm not 100% certain.

A sculpted profile like this one uses different keycap shapes for different rows. For example the Escape keycap should be taller than the cursor keycap.

If you want to replace all of the keycaps with a new set, any MX-compatible set designed for a standard keyboard should work. If you want to see the backlights properly go for a shine-through set.

There is lots more information here: https://www.keyboard.university/100-courses/keycaps-101-ydy8j