Installation via the Atlassian Marketplace
On your Jira Cloud instance, click the gear/Settings icon (Figure 1 - 1) and select Apps (Figure 1 - 2).
Figure 1 - Apps
A screen will open (Figure 1) for you to search for apps from the Atlassian Marketplace. Use the search bar (Figure 1 - 3) to look for Xray, and the result will appear (Figure 1 - 4). Click it.
The Xray screen will open. There, the Try it free button (Figure 2 - 1).
A modal will open (Figure 2).
Click the Start free trial button (Figure 2 - 2).
Figure 2 - Install
Wait for a few seconds, while Xray is added to your Jira Cloud instance (Figure 3 - 1).
Figure 3 - Added
Then you will see a success message (Figure 4 - 1): the installation is concluded, and Xray is now added to your Jira Cloud instance.
Figure 4 - Xray
See also the Quick Setup instructions.
Installation via App URL
You don't need to install Xray in Jira Cloud to use the an URL provided by Xray. Simply follow steps 1 – 3, then insert the token, in the Manage Apps screen (Figure 5) by clicking the pencil icon (Figure 5 - 1).
Figure 5 - Token
Make sure you have a project. If you're creating a new Jira Cloud instance, you may do it right away during that process.
On your Jira Cloud instance, click the gear/Settings icon (Figure 6 - 1) and select Apps (Figure 6 - 2).
Click Manage Apps (Figure 6 - 3).
Figure 6 - Manage
The Manage Apps screen opens (Figure 7). There, click Settings (Figure 7 - 1).
Figure 7 - Apps
A modal (Figure 8) will open. Select the Enable private listings option (Figure 8 - 1).
Once you're finished, click Apply (Figure 8 - 2).
Figure 8 - Modal
The Enable Private listings option can't be disabled when access tokens are installed.
Back on the Manage Apps screen (Figure 9), click the Upload app button (Figure 9 - 1).
Figure 9 - Upload
A modal will open (Figure 10). There, enter the app description URL (Figure 10 - 1).
Once you're finished, click Upload (Figure 10 - 2).
Figure 10 - Modal