This is a haplogroup project focused on R1a-Y2902 (so far equivalent to Y1392) subbranch deep downstream from Z280.
You don't have to be tested for these SNPs to join, it is enough that you were predicted to be Y2902 by the associated R1a Project.
Y2902 is estimated to be around 2500 years old and is one of the most numerous branches under CTS8816. It is most likely connected with a spread of Slavonic languages, though story of some Y2902 subbranches might have been different. We can't rule out that Gothic people spread it to some extent in the Migration Period. We can't rule out Magyars spreading it during their expansion. More aDNA is necessary to find it out
Please take a look at the map of Y2902 I have done some time ago: https://www.google.com/maps/d/u/0/viewer?mid=1wz0VcLzLVIHhz4VHNT43C3ubvpQ&ll=48.951598624587675%2C23.382861087500032&z=5
On the other hand, that is the YFull tree of Y2902: https://www.yfull.com/tree/R-Y2902/. If you did full Y-Chromosome sequencing you are encouraged to join this tree and support the research.