Learning enough html and JS to consume an API or post a form isn't that hard. You can develop an API using a client like postman, but making an effort to consume that API will make you a better dev. Besides, frontend is awesome once you stop being afraid if it.

1. Use tools like curl/postman/etc to query your APIs

2. Make an ugly frontend, just for demo purposes

3. Write tests to call your APIs

Not everything necessarily needs a frontend. Imagine you're creating a SaaS API, there usually aren't Frontends except for maybe an API testing tool

On 2, Make an ugly frontend, I learned a straightforward way to work with services and various kinds of backend code without front ends: add a simple web server endpoint to expose whatever properties, settings, or behaviors are of interest.

This is almost trivial if your chosen language has capabilities built-in, as in `python -mSimpleHTTPServer`. Add endpoints to return in plain text or maybe json. One thing I often do is log to an in-memory array of strings, then add an endpoint `/log` that returns the contents of the array. I usually go a bit farther and use a circular buffer, so the in-memory log doesn't grow too big.

Postman is a good tool also, though the learning curve can be a bit steep.

Don’t “study” it. Build something.