Axios again. Done. Registration flow seems ok.

backend/package.json

@@ -30,6 +30,7 @@
     "axios": "^0.27.2",
     "openid-client": "^5.1.9",
     "reflect-metadata": "^0.1.13",
+    "request": "^2.88.2",
     "rimraf": "^3.0.2",
     "rxjs": "^7.2.0"
   },
@@ -41,6 +42,7 @@
     "@types/jest": "28.1.8",
     "@types/node": "^16.0.0",
     "@types/supertest": "^2.0.11",
+    "isomorphic-fetch": "^3.0.0",
     "jest": "28.1.3",
     "prettier": "^2.3.2",
     "source-map-support": "^0.5.20",