For people who're still watching this thread: I don't know to replace the selling items on Nopaew shop, but I was able to find a way to get the IDs of the items, and was successfully get the Cat Express Ticket.
Basically, on this thread there are 3 things:
Hack Nopaew existing items to buy a lot of it without gems: https://sbupload.com/ea247239cf61d449
Hack Red / Green keys by locking the IDs: https://pixeldrain.com/u/YmYyqKaK
Hack items that are not in Nopaew shop by swapping the IDs, this is similar to the 2nd hack, except that you have to find the IDs for the items you want.
I'll give the steps to get the IDs you want in step 3, but I'm too lazy to record a video. If anyone can do it successfully and have the time, please help record and upload a video. I would rather share this with everyone or let the developers fix it, than letting shameless people getting benefits from this.
Here are the steps:
Download and install apk from apkpure, select the armv8 architecture. This step may not be required, it's simply the version I use since I cannot download from Google Play.
Follow the 2nd hack, you should save 3 variables: amount of item, the top 2 pointers (purple color). I believe that only the 2nd is needed, but haven't tested.
Search for the ID of the item you want to swap, I hacked only the Cat Express Ticket, so I'll share it:
Cat Express Ticket has a text ID: dungeon_ticket.skip
Search using :dungeon_ticket.skip (note the semicolon in the beginning, it means text search)
Refine the search with :. (semicolon, then dot)
There should be 2 - 6 items left
Tap on one of the results, then select Go To
On this screen, you can tap on the top right corner, in the screenshot, it's where the h,S,D,F is showing.
You can config how to display the values for the addresses in this screen, you should tick the Hex, String and DWORD boxes
Scroll it down a few addresses, pass the end of the text ID a bit, you should see 2 pointer variables (purple)
As in the screenshots, the 2 values you're looking for are 505 087 712 and 504 682 272, on my device, I can easily identify them because there are two 120D value under them, it could be different on different devices
If you cannot find these ID, try with other search results
Once you have the 2 values, replace the 2 pointer variables you saved before with these values, in their respective order. Like I said, probably only the latter matters but I didn't test.
Continue with the hack
I'm not good at Game Guardian so these steps are not that refined, and as you can see, it doesn't change the items sold in Nopaew like in the screenshots of the guys who cracked it, but the result should be the same. I hope from these steps, some smart people will refine it and share more detailed steps with everyone.
You can use the same steps to hack Opus, and I guess it's possible to hack Cat Coin this way too. All the memoirs should have the prefix: job_rank_item, (e.g: job_rank_item.zodiac_fellislord, job_rank_item.zodiac_blazehero...). You can use text search to find all of them. Another way may be to unzip the downloaded APK file, there should be a localization file that would contain similar IDs. I'll leave that to other people, as for me the skip tickets are enough, as I believe the ability to skip dungeons should be free for everyone, I don't appreciate WFS lock it behind pay wall.