Iphone entirely blocked after insstalling the app :/ I cannot work ! No reset possible, hard reset does not work eiher

I intalled the chime and doorbell with camera. Suddely the app froze my entire phone, hard reset does not work and I cannot work as my phone is broken!! I cannot work as my phone contains apps for accessing servers at work - what am I supposed to do?! Eufy whty don’t yiou pay me for a new phone and lost income at work? £2500 please. Total shambles.