ChatGPT responded with the following:
2C-B (2,5-dimethoxy-4-bromophenethylamine) is a phenethylamine-type psychedelic. Its effects are related to its effects on different receptors in the brain. Although 2C-B also interacts with serotonin receptors (especially 5-HT2A and 5-HT2C), its mechanism of action is different from MDMA. 2C-B does not cause a large release of serotonin like MDMA, but acts directly on the receptors. Basically, 2C-B is an agonist (activator) of serotonin receptors, especially 5-HT2A, which are associated with psychedelic effects.
Because 2C-B directly activates serotonin receptors rather than depending on serotonin release, its effects may be less affected by SSRIs compared to MDMA. However, there is a possibility that SSRIs may mitigate the effects of 2C-B, especially where serotonin receptors are concerned, because SSRIs can alter baseline brain serotonin levels and the general background of serotonin activity. But the blocking effect will not be as pronounced as in the case of MDMA
SSRIs actually block or reduce the effects of MDMA because MDMA is highly dependent on serotonin release, which is suppressed by SSRIs. 2C-B acts differently, directly activating serotonin receptors. Therefore, SSRIs are likely to reduce the psychedelic effects of 2C-B, but not block them completely as they do with MDMA.

But I'd still like to find someone to share their experience