For filament we can use DC or AC voltage but AC has superiority over DC. If the filament is driven with a DC voltage there will be a voltage gradient across its length. This means the end of the display with the more positive filament voltage will have less of a differential to the anodes, and thus will be dimmer than the negative end of the filament due to the potential gradient effect.

http://insanity4004.blogspot.com/2017/03/p170-dh-vacuum-flourescent-display.html

https://www.qsl.net/m0ayf/VFD-Regen.html

to producing AC voltage i decided to use a microcontroller, in this case i choose an Attiny13 .

for achieving a 5v 60hz ac voltage i programmed two pins of Attiny13 as output and switching them on/off respectively with a 8 milliseconds delay.

void setup() {

  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);

}

void loop() {
  digitalWrite(0, HIGH);
  digitalWrite(1, LOW);
  delay(8);
  digitalWrite(0, LOW);
  digitalWrite(1, HIGH);
  delay(8);
}