I just bought ROKU EXPRESS MAX 4K. Everything works perfect, except I Cannot add manually the channels I want in the first place: PRIME VIDEO, DISNEY+, HBO MAX, ESPN, STARZ, etc
In the streaming section where all categories are, there should be a SEARCH option and NOWHERE does the search option exists.
Also, I tried adding the channels on the website with my account logged in and in home page I add those channels but they do not show on the ROKU either...
nothing about adding manually channels nor finding the SEARCH tab is happening properly.
Where are you located? Search and many channels are not available everywhere. A Roku device will work anywhere, but it's usefulness may be limited.
I am in Dominican Republic now. But the point is that it is very strange that the SEACH option don't exist at all so how can I install Apps without that option? Not even Disney+ which is also a Button on the remote control.
Unfortunately, that's not a country that Roku supports. Outside their list of supported countries, you are kind of "on your own" as far as finding working content. (Including coming up with something to replace searching.) The fact, that one of the services advertised on the remote doesn't work, implies that the device was not intended to be sold there and is probably a "grey market" item.
Rokuguide website has the detailed channel code names needed to add channels via "add a channel with code" in the my account section of Roku website.
But channel may not be available as per what @Strega says.