I want to feild half length.

You can use the class form-row-first inorder to show the field half-length. Please refer to the below screenshot:

https://prnt.sc/105t7cz

If we have misunderstood your exact issue, please clarify us with more details.

Thank you!

thank for your help

and i have anather question
i create radio type for 4-6 choice
Can i make it in 1 line

https://drive.google.com/file/d/1pGuWYMJle49xLH_X2HaJbqDe5_8Jdxy1/view?usp=sharing

Please add the below style in your theme’s Additional CSS.

form.woocommerce-checkout .input-radio {
   margin-top: 10px;
}
.thwcfd-field-radio .woocommerce-input-wrapper {
   display: flex;
}

We hope this will help.

Thank you!