If you want to use Uber/Grab at DPS at minimum you need to walk from international to domestic terminal and then call Uber from departures at that location. Uber/Grab drivers WON'T come at international arrivals.

You need to have certain flexibility - expect that you won't be successful with your first or second request and you might have to wait 15-45 min until pickup and might have to travel further to the pickup point like at parking lot.

Those are current realities and nothing you can do to change them - venting at English speaking forums and writing angry messages to Uber won't help.

If you are not willing to wait/gamble and/or you are traveling to Ubud it at similar or longer distances AND you do not want to enrich airport taxi mafia/cartel, the best and only approach is to get a driver which will pick you up at arrivals and take you to the destination according to negotiated price.

There are number of recommendations at TripAdvisor forums with such drivers/rate. Current running rate from DPS to Ubud is 300K IDR and 250K - return. Rates to other places are obviously different.

I also have such driver which I have been using last three years. If you need contact- send me a message. I am not getting anything from it, just helping a guy to provide living to his family.