Tesla‘s driverless robotaxi finally hit the road this weekend, sending shares of the electric vehicle maker up about 5% on Monday.

The EV giant debuted autonomous rides in Austin, Texas, on Sunday, opening the service to a limited number of riders by invitation only. CEO Elon Musk said in a post on social media platform X that customers were charged a flat fee of $4.20.

“Super congratulations to the @Tesla_AI software & chip design teams on a successful @Robotaxi launch!! Culmination of a decade of hard work. Both the AI chip and software teams were built from scratch within Tesla,” he said in a post.

One tester wrote on X that they did 11 “smooth as butter” rides with the service with “zero issues.” Musk reposted numerous firsthand encounters with the services.

Musk has long promised a driverless Tesla robotaxi fleet to investors, amping up the pressure to deliver.

The launch puts Tesla head-to-head with Alphabet‘s Waymo, which is already operating a fleet of robotaxis in several cities across the U.S. and reached 10 million trips last month.

Musk told CNBC’s David Faber last month that Tesla aims to have “Hundreds of thousands, if not over a million” self-driving cars in the U.S. by the end of next year. In May, Musk first announced plans to launch the service in Austin, with later debuts set for Los Angeles and San Francisco.

Heading into the launch, Tesla faced pushback from a group of Democratic lawmakers in Texas and public safety activists urged the company to delay the debut.

Tesla’s full-self driving capabilities, which feature a standard FSD or FSD supervised, include automatic steering and parking, but have been linked to accidents and fatalities, according to data tracked by the National Highway Traffic Safety Administration.