How to bypass/skip payment after checkout in Ubercart?
One way to do this using the combination of ubercart custom payment module and ubercart discount coupon module, i.e creating a coupon of 100% discount and to bypass the payment process you will need the ubercart custom payment module (by default it provides the rule that can use it).
Ubercart Discount Coupons: Coupons can apply either a fixed price discount or a percentage discount to the order subtotal or to selected product prices.

Coupons are configured at Store administration &gt; Coupons. Global settings for the module are configured at Store administration &gt; Configuration &gt; Coupon module settings.

Ubercart Custom Payment module:

provides a &quot;Free Order&quot; payment method, and a default Rules configuration is provided to enable this.