* **Modify some DNS records**.
    * For this, the renewal program needs to support the APIs of the DNS provider, so, depending on the DNS provider you are using, this might or might not be an option.
* **Run as a server** (at least during the certificate acquisition process) on the public IP address associated with the domain.
    * As we said above, only one process can be listening on a specific IP and port.

    * If you depended on that previous behavior, you might need to update your code. As always, make sure your tests pass before merging the upgrade.

## 0.90.1

### Upgrades

The client will get a **500 Internal Server Error** for that request, but the application will continue working for the next requests instead of just crashing completely.

### Bigger Errors - Crashes

Nevertheless, there might be cases where we write some code that **crashes the entire application** making Uvicorn and Python crash. 💥

<img src="/img/tutorial/security/image01.png">

!!! check "Authorize button!"
    You already have a shiny new "Authorize" button.

    And your *path operation* has a little lock in the top-right corner that you can click.

And if you click it, you have a little authorization form to type a `username` and `password` (and other optional fields):

<img src="/img/tutorial/security/image02.png">

!!! note

* MySQL
* SQLite

In this example, we'll use **SQLite**, because it uses a single file and Python has integrated support. So, you can copy this example and run it as is.

Later, for your production application, you might want to use a database server like **PostgreSQL**.

!!! tip

    But it was updated to use Python-jose instead as it provides all the features from PyJWT plus some extras that you might need later when building integrations with other tools.

## Password hashing

"Hashing" means converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

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<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/tiangolo/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

"_We adopted the **FastAPI** library to spawn a **REST** server that can be queried to obtain **predictions**. [for Ludwig]_"

<div style="text-align: right; margin-right: 10%;">Kabir Khan - <strong>Microsoft</strong> <a href="https://github.com/tiangolo/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

"_We adopted the **FastAPI** library to spawn a **REST** server that can be queried to obtain **predictions**. [for Ludwig]_"

<div style="text-align: right; margin-right: 10%;">কবির খান - <strong>মাইক্রোসফ্টে</strong> <a href="https://github.com/tiangolo/fastapi/pull/26" target="_blank"><small>(ref)</small></a></div>

---

"_আমরা **FastAPI** লাইব্রেরি গ্রহণ করেছি একটি **REST** সার্ভার তৈরি করতে, যা **ভবিষ্যদ্বাণী** পাওয়ার জন্য কুয়েরি করা যেতে পারে। [লুডউইগের জন্য]_"