SharePoint Classic view via URL parameter

Is it possible to force SharePoint to use Classic experience with URL parameters?

(For example https://companyname.sharepoint.com/Lists/ListName/AllItems.aspx?ClassicExperience=True)

There is a Bookmark list that we uses on a daily basis, but some of our custom developed pages are not properly showing in the Modern experience, and our colleges have to click on “Change back to old SharePoint” link every single time.

There is a link that leads to the Classic SharePoint:

<a class="LeftNav-notificationLink" role="menuitem" data-bind="attr: { href: $data.url, target: $data.openInNewTab &amp;&amp; $data.openInNewTab() ? '_blank' : null, tabindex: $component.isLeftNavVisible() ? 0: -1, 'aria-label': $data.altText }, visible: !$data.show || $data.show(), click: $component.onClick.bind($component), automation: $data.automationId, automationType: 'Link'" href="#" tabindex="0" aria-label="Kattintson vagy nyomja le az enter billentyűt, ha vissza szeretne térni a klasszikus SharePointra" data-automationtype="Link">
<span class="LeftNav-linkText" data-bind="text: $data.text">Vissza a klasszikus SharePointra</span>
</a>