shopify extension serve giving error X No available ports found to run extension

[sadafsid]

I am trying to follow the post-purchase extension by following

this docs https://shopify.dev/apps/checkout/post-purchase/getting-started-post-purchase-extension I have followed all the steps and they are working except the shopify extension serve it

is giving me the same error continuously.

X No available ports found to run extension.

by the way I able to run the app itself with ngrok in shopify admin by shopify node serve.

but when i try with the extension it again giving me the error. any suggestion !!!

[sadafsid]

i am using widows os