At the moment, you are not eligible for a UK eVisa:

Who can set up access to an eVisa

You can set up access to your eVisa now if you have a:

• BRP
• Frontier Worker permit

Check if you can access an eVisa if you have another physical immigration document.

The link leads to another page that says in part:

To access your eVisa now, you ... need to have a certain type of immigration document.

If you do not, you’ll need to set up your eVisa later on.

And, near the bottom of the same page:

You’ll need to apply for a BRP before you can access an eVisa if you have indefinite leave to remain or enter and:

• [three inapplicable items omitted]
• you do not have or were never given an immigration document

The link for the