How to reproduce:
1. Make sure you have at least one missing module in you Editor installation
2. Open new Unity project
3. In Build Settings window, select a platform for which you don't have the module installed
4. Click "Install with Unity Hub"
5. Observe Unity Hub

Expected result: The "Add modules" window appears in Unity Hub
Actual result: The "Add modules" window does not appear in Unity Hub

Reproducible with: 2.4.5 (2019.4.29f1, 2020.3.15f2, 2021.1.16f1, 2021.2.0b6, 2022.1.0a4)
Not reproducible with: 3.0.0-beta.2 (2019.4.29f1, 2020.3.15f2, 2021.1.16f1, 2021.2.0b6, 2022.1.0a4)

Note:
Using Unity Hub's "Add modules" under Unity versions in the Installation tab allows the user to add Editor modules.