Can someone help me wiring this correct? The bell button outside is connect to I and O. When I search for devices in shelly app, just pending connection.
Manual for connecting the doorbell.
Not knowing what you are trying to accomplish, it is hard to help you.
One thing I notice, that you are trying to use the doorbell transformer’s low voltage 8 Vac to power the Shelly. That won’t work, since Shelly Plus 1 only supports 12Vdc, DC 24-48Vdc or 110-240Vac.
You have also practically shorted the “ground” (L) to the SW input of the Shelly, meaning that the Shelly switch input is always on.
Shelly I and O are the relay output, not the switch input.
And one more thing there is no jumpers to set in this Shelly model.
And as the manual for the doorbell says, ask a qualified electrician to connect it.

