You can find the panel to create a replacement rule in the bottom-right corner. Once you create a variable or a replacement rule, it will instantly start applying.
NOTE: Variables and replace rules will only apply to a project in which they were created. They do not apply globally. Also, they are saved locally at the moment, so members of your team don’t see the rules and variables you create. If you would like to have team-shared variables, please upvote it here.
Define any value in the code panel as a variable – such as colors, fonts, gradients or dimensions. Matching values will be instantly replaced by the created variable.
You can easily customize the code output using a replacement rule. You can replace anything with anything. And you can even use regular expressions.