I bought a project bike frame (Schwinn tourist) without RD hanger. I emailed Pacific cycle with the modelnumber of the bike (there was a sticker) to find out which RD-hanger I need. they replied this model has a direct-mount. I don't have any experience with direct-mount, but to me it looks like there is some piece missing. This picture shows a yellow piece i don't seem to have. Is this a direct-mount frame? and if so, do i need anything else besides a DM-RD?

I found this hanger, but it doesn't look like it would fit

That is not a direct mount. It's just a frame that's missing its derailleur hanger. It looks like the type of hanger that is attached with a chainring bolt.

I think that might work. That hanger is, of course, viewed from the reverse side in that picture. When flipped to the obverse, as you'd look at it from the derailleur side, it looks like the contours are consistent with your frame.

Here, you go. Marwi Union hanger GH-009
https://www.marwi-eu.com/gh-list-sch...ramemodels.php

I bought the same exact hanger for $4 on eBay or Amazon, for my Dahon bike.
It's cheap because it's stamped aluminum instead of CNC. It even came with the chainring bolt to attach to the frame.

I don't know if it's the correct model for your bike, but that's what the Marwi website says. There is a 1:1 full scale PDF that you can print out (make sure to select actual size, not scale to fit), cut out the paper, and stick it on your bike to see if it will fit.
https://www.marwi-eu.com/pictures/gh/gh-009.pdf

The link you shared from derailleurhanger com seems to be the same one that wheelsmfg sells. They're $22 because it's CNC instead of stamped.
https://wheelsmfg.com/derailleur-hanger-27.html
https://derailleurhanger.com/manufac...n/tourist2012/
(Edit: actually they both appear to be run by the same company)

The German sellers of the GH-009 have it really cheap for $4-5
(edit: oh the taylorwheels seller from Germany doesn't seem to have US shipping options. If you go to the Amazon "other sellers", you can find Amazon selling it too. Select US destination and usually they have an export option. Shipping is typically 10-14 days to the US.
https://www.amazon.de/dp/B00P6IIFMQ/
https://www.ebay.com/itm/Fahrrad-Sch...d/401008068168
US Seller Bike Wagon has it for $14
https://www.ebay.com/itm/Sunlite-Roa...9/274062370914

Oh, I looked a bit more, and Chinese eBay sellers have it for $2.

Whichever you choose, buy a spare.

Wow, thanks for all the advice. Better advice than I got from Pacific cycle.

I ordered a #27 hanger off ebay. I noticed some of the sellers there have #27 that look different, so always good to double-check.

I'm not 100% sure yet what to do with this bike (I just bought the frame, fork and two wheels inc. 8 speed cassette at a good price). I probably will throw some odl parts on and sell it (it is a size too small for me), so i don't want to get the CNC-machined hanger just yet.