Last year installed Signal through some tricky steps over the browser.
Now it says that I have two more days to upgrade and shall actualize the app.
Hitting the actualization button results in the msg
“No such app found.”
while I am looking on the Signal-window.
If you have installed it thru the browser, then you should also receive updates from within the app. Alot of Apps which offer download from theier website also have update feature (NewPipe, Molly). Atleast thats how I remember the Signa app before I switched to Molly.