curl --location --request POST 'https://api.freedompay.money/init_payment.php' \
--form 'pg_order_id=23' \
--form 'pg_merchant_id={{paybox_merchant_id}}' \
--form 'pg_amount=25' \
--form 'pg_description=test' \
--form 'pg_salt=molbulak' \
--form 'pg_sig={{paybox_signature}}'
# Пример подписи:
'init_payment.php;25;test;{{paybox_merchant_id}};23;molbulak;{{secret_key}}'