# Launch Zoom from your app
Normally, you would embed a meeting invitation URL in your app which
when clicked by a user, launches the Zoom app and lets the user join the
meeting.
It is also possible to allow users to launch just the Zoom app from your
app by pressing a link or a button without specifying a meeting
parameter.
Here are the ways to achieve that on iOS:
## Use URL
Parse the URL `zoomus://` and check whether it is openable or not and
then launch it. In order to be able to launch the external app on iOS (
in this case, the Zoom app), you should add
`LSApplicationQueriesSchemes` scheme as a key in the `info.plist` file:
```objectivec
LSApplicationQueriesSchemes
zoomus
```
> **Note:** If the key is missing from your app's `.plist` file, the
> following error will occur: _This app is not allowed to query for
> scheme._
```objectivec
- (void)onZoomClient
{
NSString *Uri = @"zoomus://";
if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:Uri]])
{
if (@available(iOS 10.0, *)) { // If the system OS is iOS 10.0 and above
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:Uri] options:@{} completionHandler:nil];
} else {
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:Uri]];
}
}
}
```
---