Best way to keep information secured yet shareable.

With the recent strides towards digitisation, things like insurance, funds and banking are all handled online on the phone. I am worried that in my absence my family might not be able to access all the different accounts that I use and can be helpful for them. Is there any way I can go about keeping such information secure and safe with me yet easy to access by my trusted people in an emergency/my absence? Looking for more non-subscription/online based solutions.