As with the first installment in the series, the film is originally released solely in theaters and cannot be viewed online at this time. But, there are several opportunities to view it on the big screen, as the picture is currently showing in hundreds of theaters around the nation following its release on April 1st.
The good news is that it appears 123 Movies Sonic 2 will eventually be accessible to stream, as it is slated to be offered to American streaming service Paramount Plus approximately 45 days following its theatrical release.