Thanks for reaching out, bpatelcpa.
Since you've mentioned that some Apps in the marketplace allow clients to install the apps and others don't, I would recommend you reach out to the developer of the app so someone can help you fully address your concern installing it.
I would also encourage you to visit our QuickBooks Blog to learn more about recent improvements, news, and product enhancements of our software. Here's the link: https://quickbooks.intuit.com/blog/
If you have additional questions or concerns while working in QBO, leave a comment below. I’m here ready to help you.