secure erase of data

Do not install an SSD internally. Rather, use an external SSD: How to Setup and Use an External SSD as y… - Apple Community.

Here are the Disk Utility secure erase functions: Erase and reformat a storage device in Disk Utility on Mac - Apple Support.

Jack

It's not practical to run a laptop from an external SSD, particularly when on the road. Laptops can replace internal drives much easier than Desktops.

OP said:

installing solid state drive iMac 2017.

Ooooooooooooops! I looked at his bio tag the bottom of his post and missed the iMac reference. You're absolutely right!