Using a prefix for strapi routes

Thank you for explanation. I tried and it doesn’t work. Let me reproduce the steps:

  1. server.js exactly as above
  2. cleared .cache and build folders
  3. rebuild admin panel with npm run build
  4. nginx config exactly as specified in optional software at subfolder unified.
  5. accessing example.com/ , where Open the administration button correctly links to example.com/api/admin url
  6. accessing the administratipn link results like following in console:
 Project information

┌────────────────────┬──────────────────────────────────────────────────┐
│ Time               │ Tue Oct 13 2020 22:24:48 GMT+0000 (Coordinated … │
│ Launched in        │ 2037 ms                                          │
│ Environment        │ development                                      │
│ Process PID        │ 16423                                            │
│ Version            │ 3.2.3 (node v12.18.3)                            │
│ Edition            │ Community                                        │
└────────────────────┴──────────────────────────────────────────────────┘

 Actions available

Welcome back!
To manage your project 🚀, go to the administration panel at:
http://localhost:1337/api/admin

To access the server ⚡️, go to:
http://localhost:1337/api

[2020-10-13T22:25:45.043Z] debug GET index.html (27 ms) 200
[2020-10-13T22:25:45.120Z] debug GET /assets/images/logo_login.png (6 ms) 200
[2020-10-13T22:25:45.281Z] debug GET /favicon.ico (1 ms) 200
[2020-10-13T22:25:52.463Z] debug GET /admin (3 ms) 404

Here you can see that Nginx stripped the /api part from url, but… /admin not to be found!
Suspecting that the api keyword may be a forbidden word I also tried same steps with another word. Same results.