Magento 2.4.6p2 Order confirmation emails not sending when customer places an order

I have installed “Payplus” payment gateway on Magento 2.4.6p2. When tried to place a test order the order is received fine in admin however the customer doesn’t receive an order confirmation email and an email is not sent at all from smtp. The actual extension is conflicting with the entire payment options as non of the payment options do not send order confirmation when the order is placed. When sending email manually from admin it works fine. When deleting the extension of Payplus everything is working fine again and order confirmation automatically sends out after placing an order. Please advise what should be fixed in which file and how. Your help will be highly appreciate it.