Now for the LF side of your NExT
This is a great simple tool with just a couple of limitations you need to be aware of.
They are not all created equally, they may look the same, but under the hood, they can be quite different.
The best option is the " Blue cloner " from the DT Store because it is a known entity and it gives the most amount of read write options.
If you want to just read / write EM, HID, AWID then it is perfect, if anything else like indala, prox etc… then you are better off getting a Proxmark
A limitation of the Blue Cloner is the limited range with an xSeries incl the NExT
But @anon3825968 came up with an easy and effective Mod. you can do to it to improve performance / reliability
Finally with the BlueCloner, it places a password onto your implant, This is not an issue if you only ever need the BlueCloner, but if you want to change it to anything outside of EM, HID, AWID, It is a known password and can be removed, but you need a Proxmark to do this.
Is your access badge HF or LF.
Once you answer THIS, we can help you with THAT