It's nice to have you here in the Community, @irunfree. I'll be happy to address your concern about accessing the Tasks feature in the QuickBooks Online (QBO) mobile app.
With the app, you can easily track your sales, expenses, and profits anywhere while being on the go. You may also collaborate with your team and share access to your data in real-time, making it easier to work together and stay on top of your business finances.
To view your pending tasks, go to the Today tab and tap the You have tasks to complete option.
If it's unavailable in your device, I suggest logging in to your account using a supported mobile browser. Then, go to the Tasks menu to create and assign one.
Refer to this article to compare the feature availability on supported devices: Compare mobile app features.
Furthermore, you may automate common tasks by utilizing workflows. With this, you can set the conditions to order the program when to send reminders, and to whom.
Let me know if you have clarifications about tasks. The Community is here to help whenever you need it. Stay safe and have a wonderful day ahead!