I’m not sure of the syntax you used to cause the issue you’re encountering with the compiler on your second screenshot but if you really don’t want to use simple string concatenation in your js snippet, the following syntax works: rescript playground.
This is because you are on windows, change the end line character to LF will fix the formatting issue. You can use wsl to write rescript code on windows, the ide is not worked very well on native windows, it has serious performance issue for middle or large project on native windows. And, the first problem is because %%raw only accept pure string, did you use used ${} in it?