First on the question about adding a video, upload the video to YouTube, and then post the link in your post on TFF. Videos directly cannot be uploaded to TFF.
As to the issue, "swim bladder" is very rarely the actual problem, but it is one symptom of several other problems. The issue itself may or may not b something that can be treated (example, if this is genetic, or due to an injury) but if it is due to a problem that might be treatable... . I myself have never known a fish to recover from this inability to maintain itself in the water, and sometimes it has continued for some time, other times death is fairly rapid. Other members with mor experience with problems like this will have advice.
To find which is the issue here, they will ask for more information. Tank size, fish present and numbers of each species (including the Roselines), water change frequency and volume, perhaps foods being fed, and importantly any substances entering the tank water (conditioner is one, but any others). The water conditions (amonia, nitrite, nitrate) are helpful, they look good; the pH of 6.8 is good for this species, so that is not an issue unless it fluctuates.