How to design interactions for guiding users to install an application during sign up process

Application objective

We have a mobile application where a sales employee will be able to login to see his sales stats for the month. The data available to the employee is restricted to only his own while they access the app. We will be using an authentication provider to do the authentication for the application.

User scenarios

This is what our current process is.

A user administrator will enter the employee's email address or mobile number within the web version of the application. This will send the employee a link that he can click on and sign himself up using his email address, mobile number or his socials. We already know who he is because of the link that he used to sign himself up so we can restrict the info he sees to only his own.

How do I present the workflow to him so that he signs up and downloads the application in one step?

Flow 01

Do I let him click on the link in the email, let him sign up in a web portal and at the end re-direct him to the mobile application if he has it or to the app store if he doesn't?

Flow 02

Or do I build the signup process into the mobile application? Let him click on the link and at that point direct him to the application if he has it or to download it if he doesn't have it. Then build the signup process within the mobile application.

I would like to design workflow that will make sense to the employee. Is there any best practice in this regard? Or is another, simpler option?