Airport Time Capsule used only as backup for iMac vs Router and Backup

Hello, I’m hopping Bob Timmons or someone with as much experience reads this. No offense intended to anyone else and all help appreciated.

I have an AirPort Time Capsule which has been used for :

1) My Wifi router connected to a Spectrum modem via CAT5

• I originally set it up with a unique name R&R Time Capsule
• I originally set up 2 wifi networks

2) My Time Machine backup for my iMac hard drive via wifi.

I recently had a fiber optic line installed with a ISP who provided a modem and Nokia IpV6 tower router. All of my Apple home and mobile devices, with the exception of the Airport Time Capsule have been switched over to the New Nokia tower and are functioning. I have a “Media closet” where my networking equipment is kept.

I understand that I’m living on borrowed time with my AirPort Time Capsule. However, I’d like to continue to it utilize via wifi until I purchase a suitable replacement as my iMac hard drive backup. While discussing other help issues with an Apple Sr support representative I mentioned this desire. He suggested that the easiest way to accomplish this and have my iMac still find it would be to connect it to the Nokia wifi router via Cat cable and keep it as part of my home Ethernet. I’ve connected a Linksys 5 - port switch to the Nokia router to provide additional LAN ports. The Nokia only comes with 1. I asked the Apple support sr rep if I needed to change anything in the setup of the Airport Time Capsule when connecting via cat cable to the Switch and thus the Nokia router so that my iMac could find it using the iMac’s wireless connection to the Nokia router. He suggested that no change was needed and my iMac would find it via wifi connection to the Nokia router.

This simple plug and use setup didn’t work. I’m not suggesting the Apple support rep was wrong but rather there’s probably some configuration I had made previously on the airport time capsule that prevented this easy plug and play. When I connected the airport time capsule to the Nokia router, the airport time capsule little light just continued to flash amber. I’ve began trying to troubleshoot and was led via a pop-up on the time capsule to change the router setting from DHCP/NAT to off bridge mode. I made this change and the AirPort Time Capsule light flashing amber became green.

To verify correct set up I wanted to initiate a Time Capsule backup of my iMac hard drive. Somehow in my less than skilled troubleshooting I removed the little Time Capsule icon which resided at the top bar of my iMac screen near the wifi, stage manager ,volume, etc icons. This is the only way I have knowledge of to start a backup.

I’m humbly requesting help in :

• 1) assuring that my AirPort Time Capsule is configured correctly so that my iMac can find it and utilize it efficiently
• 2) returning the Time Machine icon to the top bar of my iMac screen so I can initiate a wireless backup to verify correct setup.
• any other configuration changes on the AirPort Time Capsule I should make.

Thank You