Hi @Stewartgrace , welcome to community! 
While Bitwarden can offer to save the last-used credentials using your web browser, we do not currently support and offer that on iOS.
If this is something you’d love to see on our roadmap, I’d recommend voting for this Feature Request: Ask to add login and Ask to update existing login for iOS
As you also mentioned you’re still transitioning, I wanted to let you know about our guide to exporting from your old solution and importing to Bitwarden in our Help Center. 