So much easier with pictures! Yep, that’s right. You will need the top one rather than the bottom one that you have for a 15mm axle. In which case you will need a tool similar to the one in my link if you don’t already have a bb tool. You will need the spanner rather than the type that fits over the whole bb. That won’t get over the axle to reach the CL lockring unfortunately.
I though that the hubs should have come with lockrings since they are not the type that the rotors come with. Might be one to take up with whoever sold you the hubs/wheels although the replacements are not expensive. I have the XTR versions (came with the hubs) which are identical to the Deore version in all but colour.