Dependency injection pattern how to initialize variables of static class at beginning

I've been using dependency injection for about 6 months now and sometimes there is a situation I don't know how to handle in an elegant way.

Say I want a class for storing all my app settings in. This class is only initialized at beginning.

Please let me know how idea 1 can be executed (as I think this is the classic way) and if idea 2 is a valid pattern or if there is a better alternative.

Idea 1:

make this class static as its variables are only initialized and after that everything stays read-only. The problem with this is that I do not know where to initialize variables of this class. To initialize one of the variables a password needs to be decrypted which requires the use of IEncryption interface.

I would like to initialize these static variables before the main program actually start (so preferably in Startup.cs). I can't do that because I can't get the implementation of IEncryption in the DI container class, or at least I don't know an elegant way to get it. How should this be done with a static class? should I make another "middleware" between Startup and actual program logic where I can initialize static variables?

If I'm not mistaken simple data only classes that are application wide are ok to be static object even when using DI pattern

Idea 2:

Now I don't know if this has a name or if it's ever used. It's just something I came up with and it seems like a good solution for me but there might be an alternative I don't know of that makes it useless.

What if I instead of making this class static I make it as a normal class and initialize all static variables inside class constructor.

So something like this:

public ClientData(IConfiguration configuration, IEncryption encryption)
{
    var section = configuration.GetSection(nameof(ClientData));
    EdgeUrl = section.GetValue<string>(nameof(EdgeUrl));
    EdgeAuthUrl = section.GetValue<string>(nameof(EdgeAuthUrl));
    Username = section.GetValue<string>(nameof(Username));
    Password = encryption.Decrypt(section.GetValue<string>(nameof(Password)));
    OrganizationKey = section.GetValue<string>(nameof(OrganizationKey));
}

public string EdgeUrl { get; }

public string EdgeAuthUrl { get; }

public string Username { get; }

public string Password { get; }

public string OrganizationKey { get; }

I then inject IEncryption through the constructor.