In 2019, Marco Vieth the author of the first Amstrad CPC forr msdos (now maintained by Rainer Lortiz) did release CPCBasic unchained which is converting a Locomotive Basic program of an Amstrad CPC in javascript to use it on a web site.
This version only receive bugs fixes, it's now CPCBasicTS unchained (TS for TypeScript) which is developped, and a new version 0.1.1 was released two weeks ago.
At least I have installed CPCBasicTS and the first exeample will be one of the best Locomotive basic program which will feel you good : sound of waves and gulls by D. CARDON which came from a french magazine. Modify the number at the end of line 30 if you want to hear less gulls, and click on the Run button to launch the program.