TLDR; You don't. You need to go to unifi.ui.com. See steps on how to do it from the Android App below

I have a Samsung S24. This is how I view the Unifi VPN Sign-In logs:

Open the Unifi App

Make sure you have selected the right site / controller

Select the gear icon (bottom right)

On the settings page scroll right to the bottom

At the bottom of the screen find "Access more settings on unifi.ui.com"

Click the unifi.ui.com link

Close any upgrade pop-up nags.

There is a row of icons near the top of the screen. Click the logs icon on the far right.

To the right of the search field. Tap Critical (on my device Critical is truncated e.g. Critic)

On the Drop Down list click VPN (on my device I can only see "V" but it is enough to tap it and you can see the VPN sign-in logs on Android)

If you search this on Google the AI Overview answer is "factually incorrect" as they say