There are several options to choose from on the Chrome Web Store. When researching which extension to use, carefully review the features, look at any screenshots to see what the UI offers, and consider any permissions it requires. Here are a few popular options that should get the job done.
When the extension has been added, restart Chrome. Make sure it's enabled by going to the menu in the upper-right corner using the icon with 3 dots. Navigate to Settings then Extensions.
The extension will likely add an icon to the top of your Chrome browser window. Start there and test your new screen recording extension.