@Administrator, Thanks for posting in Q&A. For the Available for install status, please check if you assign with the assignment type "Available for enrolled devices". If yes, this needs to install the app from the Company Portal app or website. You can change to "Required:" assignment type to install it automatically.
https://learn.microsoft.com/en-us/mem/intune/apps/apps-deploy#assign-an-app
For the "Waiting for install status", it can be the app is deployed, the end device is installing. Intune is waiting for device to send its install status. we can wait some more time and go to the app deployment report status to see if the status is updated.
Hope the above information can help.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.