Cisco SG350 – How to Connect (Stack) Two Cisco SG350 Switches Together

I am building a storage network, physically separated from the data network. I have two Cisco SG350-28P-K9 V02 switches:

• One on the basement. Has two NAS, two ESX servers. (in use)
• One on the 4th floor. Has one NAS, two ESX servers. (to be added)
• Two runs between basement and 4th floor: one fiber, one ethernet.

I am trying to have the two switches work as one, so that all NAS / Servers can see each other across the two floors. Should I stack them? if so, I don't see any settings to do this on the advanced GUI, not the console.

Can you shine some light on how to archive this? Thank you!

Info Switch 1:

System Description: SG350-28P 28-Port Gigabit PoE Managed Switch    
Host Name:  vmswitch1   Edit
System Object ID:   1.3.6.1.4.1.9.6.1.95.28.5   
System Uptime:  216 day(s), 18 hr(s), 34 min(s) and 21 sec(s)   
Current Time:   14:57:17;2019-Oct-15    
Base MAC Address:   00:7e:95:52:c6:78   
Jumbo Frames:   Enabled 
Firmware Version (Active Image):    2.4.5.71
Firmware MD5 Checksum (Active Image):   2dff89efdb2a0ec2f9a2c414ff7d401c
Firmware Version (Non-active):  2.3.5.63
Firmware MD5 Checksum (Non-active): 5881484e04bcdcc17c32872445e3ab8d

Here is info on switch 2:

System Description: SG350-28P 28-Port Gigabit PoE Managed Switch    
System Location:    IT Closet
Host Name:  vmswitch2
System Object ID:   1.3.6.1.4.1.9.6.1.95.28.5   
System Uptime:  3 day(s), 21 hr(s), 33 min(s) and 13 sec(s) 
Current Time:   14:56:03;2019-Oct-15    
Base MAC Address:   2c:73:a0:fd:dd:6b   
Jumbo Frames:   Enabled 
Firmware Version (Active Image):    2.4.0.94
Firmware MD5 Checksum (Active Image):   6f5be217100f34929986f2e93dd2d5e9
Firmware Version (Non-active):  2.4.0.94
Firmware MD5 Checksum (Non-active): 6f5be217100f34929986f2e93dd2d5e9