How do I install adobe flash in ubuntu disco chromium 73.0.3683.103. I tried to install but now all websites with flash have right click to play but right clicking does nothing
Might be a better question for the Chromium team, but you might try allowing Flash through the lock/info icon in the address bar, then refreshing the page.
General instructions on enabling Flash in supported browsers:
Okay the issue lies with the chromium sandbox. --no-sandbox "fixes" it
That seems sub-optimal. You might want to ask the Chromium community if there's a better recommendation. I'm curious about the outcome, but don't have a lot of insight to offer. Ubuntu has a big enough distribution that if this is a common issue, they should be well aware of it.