[NUC] Can I upgrade my ROG NUC storage and/or memory?

Yes. Memory requirements: Supports two 1.1 V DDR5 SDRAM SO-DIMMs with gold plated contacts 5600 MHz Unbuffered, non-ECC Single-sided or double-sided Maximum memory: up to 64 GB capacity.
 

Storage requirements: Supports up to 3 M.2 22x80 (key type M) PCIe Gen 4 SSDs. 
 

See the Technical Product Specification for more details on how to open system and install storage device(s).