At least as of 2 years ago, you could go to chrome://extensions, click a "Dev Mode' toggle in the top right, and sideload a downloaded crx (I know from installing https://adnauseam.io/ every time I had to use a Chromebook, it’s banned from the webstore for adding obfuscatory privacy enhancements designed as research by Daniel C. Howe and Helen Nissenbaum to gorhill's great µBlock Origin).