fnc

timer_on_hour:
 value_template: '{{ states.input_number.timer_on_hours.state | int }}'
timer_on_min:
 value_template: '{{ states.input_number.timer_on_min.state | int }}'

fnct: >
 function(on_min_state) {
  {%- if on_min_state|length == 1 -%}
     0
  {%- endif -%}
    {{ on_min_state }}
 }

timer_on_clock_start:
 value_template: >-
  {{ states.sensor.timer_on_hour.state }}:
    f <-function() {
     fuunction(timer_on_mint)
    }

    }
node2:
  value: 6
  # can be named if you prefer, though that will have no impact
  fnct: >
    DoCalculate <- function(node) {
      node$value * 2
    }