It's nice to see you in the Community space, @sales88-gulfiron.

I'm here to share some information on how to find the App's button in QuickBooks.

To start, may I know what country you used upon creating a QuickBooks Online account? This will help me determine if your region is one of the international versions that support app integration. 

QuickBooks Apps are available in the United States, United Kingdom, Canada, India, Australia, and France. If your subscription belongs to one of the countries I mentioned, you can use this link to search and get overviews of our third-party apps: Apps Center. Or navigate your cursor to the Apps menu located from the left navigation pane.

Otherwise, it isn’t available in your country that's why you can't find the Apps button.. As a workaround, you can look for a third-party app outside the program that can integrate with us. 

While we don’t have a specific time frame as to when this will roll out, I recommend checking our Firm of the Future page regularly to stay updated on any news and releases.

Furthermore, you can browse some articles on this website to learn tips for your future tasks: Help articles. This will guide you as to which section of QuickBooks you need help with.

You can always get back to me here if you need further assistance. I'm more than happy to help. Take care!