Did you read this thread, it has the correct dosing? Just asking...Hey I using this dewormer for gapeworm it this hoarse stuff I going to give her a pea sized paste in her mouth how many times a day and she small and not really eating barley drinking
"Pea Size" is not a dose.
You already have a 2 page thread asking for help, you've been given the correct dosing and have also been urged to consider that your hen may have respiratory illness instead of Gapeworm. https://www.backyardchickens.com/threads/bird-gapeworms-help.1603540/page-2
This is the correct dose, it's by weight.


Dose for Chickens would be 0.23mg per pound of weight given orally once a day for 5 days, this will treat most worms that chickens can have, except for Tapeworm.