Audio AMP Datasheet help
The Undervoltage Protection (UVP) function is intended to avoid noises on the speakers during the power-up and power-down phases.
If you provide a low voltage on the UVP pin, the amplifier will be muted, and noises will be avoided.

If these noises are not an issue for you, you simply can ignore this function, and disable it leaving the pin open, or connecting it to a logic high level.

If instead you have to avoid the noises, that can rise for instance from uncontrolled voltages on the PWM pins during power up, you must find a way to provide a control voltage on the UVP pin; the simple circuit with resistors and capacitor illustrated on the datasheet can do the job. You can start with 100k for R3 and 10k for R1 and R2, and then adjust the values experimentally.