In the upper navigation bar, click on the cog icon and select Manage apps → Find new apps

The Atlassian Marketplace page will be displayed, in the search bar type in Last Log for Jira

The app will appear on the list, select it, and install it for free

After the installation, stay on the manage apps page, on the left-side navigation bar you will find Last Log features under LASTLOG-ADD-ON

The app is ready to use and you're ready to get started!