add following weight based shipping

Hi dear supporters, I’m in a really major issue regarding my employment because of this requirement so i would like to kindly have someone for this help. Im an ultimate user but support getting there is so late and im running out of time. so i will submit the following question here.

I need to add this shipping rule(First 1Kg = $5 | more than 1KG $2 per KG)

But wcfm doesnt support this rule
when i use a third party plugin for calculation it doesn’t support for commission which is shipping cost doesn’t go to vendor it goes to admin even when i have enabled the option to have vendor the shipping cost in settings page)

I really need to add this shipping rule with shipping cost going to vendor. Please please help me with this. This is regarding my job :((((((((((((((

when i open a premium ticket they told me this

” I’m sorry but such a progressive weight-based rule isn’t supported. Though you can use the following filter to add your own custom logic- ”

apply_filters( ‘wcfmmp_shipping_weight_calculate_amount’, $amount, $price, $products, $destination_country, $destination_state, $weight_array_for_country, $default_cost_for_country, $total_weight, $weight_mode_for_country, $unit_cost_for_country );

BUT i dont know how to do this. please someone help me with this i really appreciate the help

Thank You
Christina