TL;DR. You need an AD-E1 adapter to use most flash gear with an R50.
The R50's hotshoe is missing all five of the electrical contacts your flash gear needs to communicate with the camera:
It's using newer edge contacts instead:
Welcome to the wacky world of Canon messing with hotshoes. Buckle in, it's a bit of a history lesson.
With the rise of mirrorless, came the rise of video. Flash is useless for video, and a flash hotshoe is a great place to attach video accessories like a microphone, monitor, or small LED lights. But these accessories require cording to ports and power. Sony came up with the idea that instead of using the traditional "floor" contacts/pins that every one (except Minolta) had been using for decades, to add a row of 20 or so small contacts tucked beneath a lip at the back edge of the hotshoe/front edge of the flash foot that could be used to supply power and communicate everything for all these accessories and flashes with the camera. Thus was the Sony multi-interface hotshoe born.
Canon saw what Sony was doing, and when they developed the second generation of EOS R bodies, the R3 had the first multi-function hotshoe. Unlike Sony (who moved from the Minolta iISO hotshoe), Canon could also make their new hotshoe backwards-compatible with older Canon flash gear by retaining the traditional five contacts on the "floor" of the hotshoe, in addition to adding the new edge contacts.
However. Back in the final generation of Canon dSLRs, the three lowest entry-level bodies, the SL3 (250D), T7 (2000D), and T100 (4000D) all had their flash hotshoe sync contact removed. We're not sure why, but the popular theory was to render 3rd-party flashes useless, since that sync contact is how camera tells the flash to fire, and is an ISO standard for flash hotshoes. It didn't even work; Godox got around it with firmware updates (at least for the T7 and T100. With the SL3, they only got their transmitters to be compatible).
But now Canon has gone for total traditional contact removal on the R50. Its hotshoe only has the new multifunction contacts. They probably hope the majority of R50 users will be videographers.
So, at this time, we have three different flash hotshoes on R bodies:
Traditional Canon five-contact hotshoe (like the dSLRs):
- R
- RP
- R5
- R6
- R100
Multi function hotshoe that retains the five contacts for backwards compatibility:
- R3
- R7
- R10
- R6 Mark II
- R8
The new multi-function hotshoe without the five contacts:
- R50
Multi-function Stuff
Multi-function-footed flash Canon gear that cannot be used on the traditional hotshoe:
- EL-5
- ST-E10 transmitter
- OC-E4A off-camera multi-function shoe cord
- AD-E1 adapter (to put traditional five-pin Canon flash gear onto the multi-function foot and either maintain weathersealing [EL-1, 600EX II-RT) or add compatibility [R50]).
Multi-function footed video gear:
- DM-E1D microphone
- AD-P1 smartphone link adapter
- TASCAM CA-XLR2d-C (XLR microphone adapter, Canon version)
So, to use any traditional Canon flash gear on an R50 hotshoe, like say, Godox gear, 3rd-party radio triggers, or any of the Canon speedlights/triggers other than the EL-5 and ST-E10 (and presumably any future Canon flash gear), you need to use an AD-E1 adapter.