Normally it is straightforward to connect the asensei app to your Bluetooth enabled PM5 monitor - you simply start your workout and when asensei asks you to turn on Wireless on your PM5 you follow the instructions by turning it on and enabling the wireless (if required). Sometimes issues do occur, this guide will try and walk you through some potential problems.
The PM5 should only connect to one app at a time
The PM5 won't work consistently if connected to multiple apps. If you are running another rowing app such as ErgData on your phone, you need to close that down before you connect to asensei.
You should kill any other app connected to the PM5, even if it is running in the background. To check they are not running in the background, either double-tap the home button on your iPhone, or swipe up from the bottom of the screen on newer iPhones. You can then swipe left and right through all of the apps running in the background on your phone. If you see another rowing app like ErgData, you can close/kill it by swiping it up to the top of the screen.
Connect within the asensei app not through your phone's Bluetooth settings
If you have at any time paired or connected your PM5 via the Bluetooth settings on your phone this will cause a problem. To check this go into your iPhone/iPad's settings app, choose Bluetooth and look to see if you see a PM5 Monitor listed on the My Devices list. If you see it on that list tap on the text to the right of it saying Connected/Not Connected and then choose Forget This Device.
When I try to connect I can't see the turn Wireless on option
When you press Menu, More Options on the PM5 you will normally see the Turn Wireless On option. I that doesn't appear and you are definitely using a PM5, then you need to update your monitor's firmware. See this article for more details: Can't see "Turn Wireless ON" option on my PM5
I don't even need to press turn wireless on and my PM5 connects to asensei
More recent versions of the PM5 firmware start to advertise that they are available via Bluetooth whenever you are on the home screen on the monitor (e.g. if you simply turn it on). If this is happening when asensei attempts to connect then you should be connected automatically. Pressing Turn Wireless on will still work, it's just not always necessary.