Sileo is an ideal marketplace for developers to showcase apps, tweaks, and themes that Apple would never allow in the App Store. While these are jailbroken apps that cost money for your iPhone. Sileo also wants feature payment support for you to buy tweaks within the app. Unfortunately, Sileo is still in his beta stages, so it's up to you far from a final product.
Option 1: Purchase Tweaks from External Repos
Processing payments for tweaks found within external repositories like Packix and Dynastic are done outside of Sileo, so before you can buy anything, you'll need to add the repo to Sileo first on your iPhone.
After the repo has been added, you've got a paid tweak you want, tap "Purchase" in the tweak's listing page. Next, log in to either your Facebook, Google, or Discord when prompted. This is an iPhone or have additional jailbroken devices.
After you've signed in, you'll be taken to a PayPal checkout page, so either enter the required payment details or log in to your PayPal account, then follow the prompts to complete your purchase.
Because the source repo is outside of Sileo, you'll need a link to your device bought. To do so, tap on the green "Link via Profiles" button in the repo page, then tap "Allow" on the permission prompt that appears to proceed. Note that you can also "Link via Cydia," but if you're using Sileo exclusively, that does not make much sense.
You get to the Settings app afterward, so hit "Install" in the upper right, then tap on "Install" again to confirm installation. Once the profile is installed, you'll be redirected to the repo's Safari page once more.
As far as refunds go, you have the option of
Option 2: Purchase Tweaks Found Within Preinstalled Repos
Unfortunately, the ability to purchase tweaks from native repos like BigBoss is not currently supported on Sileo due to its beta status, which means you'll have to rely on Cydia to do so. Cydia has shut down its in-app payment system as of December 2018, so you can no longer buy tweaks from native repositories.
Option 3: Access Cydia Purchases in Sileo
Even if you can not buy it directly from Sileo or Cydia, you can still buy it from Cydia. Open Sileo, then tap on the avatar icon on the upper right within the "Features" tab. Next, select "Sign in to Cydia Store," and sign in to either your Facebook or Google account.
After signing in, you'll be able to see your list of purchased apps by tapping on "Installable Purchases" within your account page. Bear in mind that the process of syncing your Cydia purchases in Sileo is automatic, which means you're free to install your pre-purchased tweaks – as long as you're compatible with your iOS version – without needing to pay again.  How To Purchase Tweaks & Apps That Work With Sileo for Jailbroken iPhones ” width=”532″ height=”532″ style=”max-width:532px;height:auto;”/>