A meta analysis of 15 studies comparing therapy in person with telephone therapy showed no significant differences between telephone and in person therapy. See this link:

https://www.nationalelfservice.net/treatment/digital-health/telephone-face-therapy/

Research carried out by the EMDR Association also indicates that online therapy is effective. See this link:

https://emdrassociation.org.uk/a-unique-and-powerful-therapy/covid-19-information-for-clients/

There is evidence for the effectiveness of online CBT. See this link: 

https://www.researchgate.net/publication/51231096_Efficacy_and_effectiveness_of_online_cognitive_behavioral_treatment_A_decade_of_interapy_research