| `apikey` | text | Your API token / key (APP_TOKEN) to access the Pushover Message API. **mandatory** |
| `user` | text | Your user key or group key (USER_KEY) to which you want to push notifications. **mandatory** |
| `title` | text | The default title of a message (default: `openHAB`). |
| `format` | text | The default format (`none`, `html` or `monospace`) of a message (default: `none`). |
| `sound` | text | The notification sound on target device (default: `default`) (see [supported notification sounds](https://pushover.net/api#sounds)). This list will be populated dynamically during runtime with 21 different sounds plus user-defined [custom sounds](https://blog.pushover.net/posts/2021/3/custom-sounds). |
| `retry` | integer | The retry parameter specifies how often (in seconds) the Pushover servers will send the same emergency-priority notification to the user (default: `300`). **advanced** |
| `expire` | integer | The expire parameter specifies how long (in seconds) your emergency-priority notification will continue to be retried (default: `3600`). **advanced** |
-`sendAttachmentMessage(String message, @Nullable String title, String attachment, @Nullable String contentType)` - This method is used to send a message with an attachment. It takes a local path or URL to the attachment (parameter `attachment`**mandatory**). Additionally you can pass a data URI scheme to this parameter. Optionally pass a `contentType` to define the content-type of the attachment (default: `image/jpeg` or guessed from image data).
-`sendAttachmentMessage(String message, @Nullable String title, String attachment, @Nullable String contentType, @Nullable Duration ttl)` - This method is used to send a message with an attachment and TTL. See previous method for details.
-`sendURLMessage(String message, @Nullable String title, String url, @Nullable String urlTitle)` - This method is used to send a message with an URL. A supplementary `url` to show with the message and a `urlTitle` for the URL, otherwise just the URL is shown.
-`sendURLMessage(String message, @Nullable String title, String url, @Nullable String urlTitle, @Nullable Duration ttl)` - This method is used to send a message with an URL and TTL. See previous method for details.
-`sendMessageToDevice(String device, String message, @Nullable String title)` - This method is used to send a message to a specific device. Parameter `device`**mandatory** is the name of a specific device (multiple devices may be separated by a comma).
-`sendMessageToDevice(String device, String message, @Nullable String title, @Nullable Duration ttl)` - This method is used to send a message to a specific device with TTL. See previous method for details.
-`sendPriorityMessage(String message, @Nullable String title, @Nullable Integer priority)` - This method is used to send a priority message.
Parameter `priority` is the priority to be used (`-2` = lowest priority, `-1` = low priority, `0` = normal priority, `1` = high priority, `2` = emergency priority; default: `2`).
For priority `2` only, the action returns a `String` value (the `receipt`) if the message was sent successfully, otherwise `null`.
For other priorities, the action always returns an empty `String`.