Technically the keycaps can be removed, but it is risky if you don't do it correctly because the parts are very fragile & easily damaged. Safely removing the key caps is one thing, reattaching them is another thing as that is another time where the key cap & scissor mechanism can be damaged. There is a certain way to remove eadch key. Some keys may need to be removed in a different manner than another key on the same laptop. The larger keys are even more difficult. I have no idea whether there are any spare parts available for this model if they are damaged (there are for older models, but every model is different....sometimes there are multiple variations for a single model).
Unless you have something large stuck beneath the keycap or sticky residue in the mechanism or around the edges, it should not be necessary to remove the keycaps. Definitely try the suggestion by @Jack-19 first. Keep in mind if you damage anything, the repair may not be cheap. Sometimes Apple or an AASP will not replace keycaps or scissor mechanisms if damaged which in that case will be an expensive repair to replace the Top Case Assembly (easily $400+ US).
If the issue is only with a couple of keys, then check with Apple or an Apple Authorized Service Provider to see whether they will clean those few keys. If a majority of keys are affected, then it really makes no sense for a tech to clean them as it will be easier to replace the Top Case Assembly which includes the keyboard.