Remove only one coupon from multiple from cart in magento 2

Question

I am using magento 2.3.4 and and I have added one coupon code by default. I want to remove this on select of payment gateway but may be customer could add multiple coupon code , but I want to remove only one not all. So how we can do this? I dis some google and get this solution

 $quote = $observer->getEvent()->getQuote();
//remove coupon code
$quote->setCouponCode('');
$quote->collectTotals()->save();

But this will remove all the coupon. I want only one, if 2-3 coupon applied.

Answer 1

Logically, you can First get list of applied coupan codes.

$quote = $observer->getEvent()->getQuote();
$couponCode = $quote->getCouponCode();

then save existing coupans in an array. and remove all coupans

$quote->setCouponCode('');
$quote->collectTotals()->save();

then apply one by one, just don't apply desired.

$quote->setCouponCode('your_coupan');
$quote->collectTotals()->save();