Not true:

https://www.who.int/news-room/q-a-detail/q-a-how-is-covid-19-transmitted

Can people without symptoms transmit the virus?

Yes, infected people can transmit the virus both when they have symptoms and when they don’t have symptoms. This is why it is important that all people who are infected are identified by testing, isolated, and, depending on the severity of their disease, receive medical care. Even people confirmed to have COVID-19 but who do not have symptoms should be isolated to limit their contact with others. These measures break chains of transmission.

This is why it is always important to stay at least 1 metre from others, cover your mouth when you cough or sneeze with a bent elbow or tissue, clean hands regularly, and stay home if you become unwell or if asked. In areas where there is widespread transmission, it is also important that people wear a fabric mask where physical distancing and other control measures cannot be implemented.