Add docs for Backblaze B2 integration

.vscode/cSpell.json

@@ -11,6 +11,7 @@
     "autodiscovery",
     "autoheal",
     "automations",
+    "Backblaze",
     "balloob",
     "bloomsky",
     "Bluesound",

source/_integrations/backblaze_b2.markdown

@@ -0,0 +1,83 @@
+---
+title: Backblaze B2
+description: Instructions on how to setup a Backblaze B2 bucket to be used as a backup location.
+ha_release: 2025.10
+ha_category:
+  - Backup
+ha_iot_class: Cloud Push
+ha_config_flow: true
+ha_domain: backblaze_b2
+ha_codeowners:
+  - 'ElCruncharino'
+  - '@hugo-vrijswijk'
+ha_integration_type: service
+ha_quality_scale: bronze
+---
+
+The **Backblaze** {% term integration %} enables you to use a [Backblaze B2](https://www.backblaze.com/cloud-storage) bucket as a backup location in Home Assistant.
+
+## Prerequisites
+
+This integration requires an existing B2 bucket and an application key that has access to that bucket. It is recommended to create a key that only has access to the required bucket and prefix (if desired).
+
+{% details "Create a new B2 bucket" %}
+
+1. Log in to the [Backblaze Console](https://secure.backblaze.com/b2_buckets.htm).
+2. [Create a bucket](https://www.backblaze.com/docs/cloud-storage-create-and-manage-buckets).
+   - Choose a unique **bucket name** (such as, `home-assistant-backups-123456`).
+   - Make a note of the bucket name — you’ll need it later.
+3. Adjust the settings:
+   - **Set bucket to private**: Enabled by default, recommended.
+   - **Encryption**: This enables Backblaze's server-side encryption. This is separate from the Home Assistant backup encryption. This is optional. If Home Assistant backups are configured to use encryption, you can disable this.
+
+{% enddetails %}
+
+{% details "Create an application key" %}
+
+To create an application key that can access the bucket:
+
+1. Go to [**Application Keys**](https://secure.backblaze.com/app_keys.htm) in the sidebar.
+2. [Create a new application key](https://www.backblaze.com/docs/cloud-storage-create-and-manage-app-keys).
+   - Use a name like `home-assistant-backup`.
+   - Limit access to the bucket by selecting it from the **Choose a bucket** dropdown.
+   - The type of access should be **Read and Write**.
+   - **Allow List All Bucket Names** can be left unchecked.
+   - Optionally, you can limit the key to a specific prefix (such as `home-assistant-backups`) if you want to save backups in a specific folder within the bucket.
+3. Save the **Key ID** and **Application Key**. You'll need these when setting up the Backblaze integration in Home Assistant.
+
+{% enddetails %}
+
+{% note %}
+
+By limiting credentials to a specific bucket, you reduce risk and help keep your Backblaze account secure.
+
+{% endnote %}
+
+{% include integrations/config_flow.md %}
+
+{% configuration_basic %}
+Key ID:
+   description: "The access key ID for your Backblaze account."
+Application Key:
+   description: "The application key for your Backblaze account."
+Bucket Name:
+   description: "Bucket name to store the backups. Bucket must already exist and be writable by the provided credentials."
+Prefix:
+   description: "Optional prefix for the backups. This is useful if you want to store backups in a specific folder within the bucket."
+{% endconfiguration_basic %}
+
+## Troubleshooting
+
+### Expired keys
+
+If the application key expires, you will need to create a new one and update the integration in Home Assistant.
+
+### Files are being overwritten due to non-unique bucket prefix
+
+If you set a prefix, all backups will be stored under that prefix in the bucket. Ensure that the prefix is unique to avoid overwriting other files. Changing the prefix will not move existing backups.
+
+## Removing the integration
+
+This integration follows standard integration removal. No extra steps are required.
+
+{% include integrations/remove_device_service.md %}