Sim card manager is missing

[SPR2021]

My S21 Ultra 5G do not display Sim card manager menu option. I bought it in Canada, right now I am in Phillipines

My devices has just une physical sim slot. 

Need help to fix the missing, essential, feature, please.

[SamsungRightCare]

Hi! I'm Sam, your friendly Samsung Customer Service guy. Welcome to Samsung Members Community! Explore your new hub for all things Samsung and beyond. Earn the coolest badges and enjoy awesome perks from us by connecting with Samsung experts, super-fans, and other Community members for tips on features and how to get the most out of your Samsung product. Should you need technical assistance, don't hesitate to reach us via our TOLL-FREE mobile number #GALAXY (#425299) or via our TOLL-FREE LANDLINE: PLDT Toll free : 1-800-10-726-7864 Globe Toll Free : 1-800-8-726-7864 Standard Landline : (02)8-422-2111 Daily (8:00 AM to 8:00 PM) or via LIVE CHAT SUPPORT: https://livechat.support.samsung.com/Customer_new/PH 

As per your concern, does your device already undergo to region unlock? 

[SPR2021]

Hi Sam, I don't know, please tell me how to check. It was sold as Internationally unlocked. In Canada I used just one SIM. But now, I really need to enable the eSIM. I visited a Samsung customer service and they required a factory reset, without giving me any warranty that will work after.