MBED_RPI_PICO_TimerInterrupt has just been published to support RP2040-based boards, such as Nano-RP2040-Connect, RASPBERRY_PI_PICO, ADAFRUIT_FEATHER_RP2040 and GENERIC_RP2040, using Arduino-mbed RP2040 v2.1.0+ core.
Also check topic MBED_RPI_PICO_TimerInterrupt library in this Arduino forum.