Vostro 3470, what type of M.2 SSD can I install?

Would like to add that after the local h/w person opened the PC chasis and checked the motherboard, it mentions both 2230 and 2280 on it and the M.2 slot itself has only one notch and seems like it has the 'm' key edge connector not 'B' and 'M' key edge connectors as shown in another post (initiated by me last year) here https://www.dell.com/community/Vostro-Desktops/Does-Dell-Vostro-3470-Desktop-have-M-2-port-with-NVMe-support/m-p/8300053#M5612. There is no option to upload a picture here hence can't share it. Has anyone with this Dell Vostro 3470 Desktop PC installed an SSD ? If so, what type was it ? Please share your experience for more clarity. Am pursuing this mainly because SSDs are sold online on a non-returnable basis, so don't want to buy the wrong one and lose money.

Any guidance from experts on this is much appreciated. Thanks

I have the same confusion and haven't been able to buy an SSD for my Dell Vostro 3470 Desktop PC. on checking the motherboard, I noticed that the M.2 SATA1 slot has only the 'M' edge connector not the 'B' edge connector as well. So, I can't buy the M.2 SATA 2280 SSD with BOTH 'B' and 'M' edge connectors. Strangely, SSDs without the 'B' edge connector (i.e. only 'M' edge connector) are all NVMe SSDs which won't work in this PC, unless one uses an NVMe to SATA adapter, as mentioned in an earlier post by someone. But, considering the fact that only NVMe SSDs have 'M' key connector not sure if this is the only option, i.e. to buy any M.2 2280 NVMe SSD and use it with the NVMe to SATA Adapter.