Retain the Session created by Shopify while creating Shopify Apps

[Codaemon]

Hello,

Currently, we are developing a Shopify Apps that will link to another server and we will embed those pages into an iframe from the Shopify App. The server is an AWS hosted with Ubuntu and the custom server is developed with PHP Laravel framework and we are integrating the laravel-shopify package for Shopify auth into Laravel system.

But below are some challenges and doubts that we are facing and would like to know how we can overcome these issues:

a) On creating Shopify Apps, we have added the home page URL of the custom server and in that, we are requesting the user (ie.shopify user) to log in to the custom server, where we also keep the session, but the issue we are dealing with is whenever we refresh or recalls any app page by clicking app link from Shopify, the Shopify creates the new session on every page load.
So wanted to know how to overcome this issue.

b) Is there any provision to always pass an access token with the Shopify app URL so that we can fetch it on the custom server, the motive is that we will create a dynamic token and then the Shopify App url will pass this token always to the custom server.

So would like to know below:

i) Is there a way to store the passed token within Shopify?

ii) How we can pass this stored token always with the Shopify app URL from the Shopify?

c) Also, while we redirect to the other pages within the custom server, how we can change the Shopify app urls by adding some slug so that on page refresh of Shopify admin will land on that particular page of the custom server.

So kindly help us in resolving these issues, means any settings or custom code examples will be helpful.

Looking for your kind cooperation and quick response.