How to register as a developer

I am attempting to set up WPLister
In order to do this I need to obtain -
AWS Access Key ID:
Secret Key:
When I view ‘User permissions’ I see my seller ID but no credentials
Thus the required info is not available to me

If this is due to me not being a registered developer - When I click the ‘Apply to be a developer’ button, I am taken to url = https://sellercentral.amazon.co.uk/mws/register/warning
And from this page I do not know how to proceed as I am not a developer
If I need to proceed by using information in this page can you please let me know which flow I need to follow, I have 2 x choices
1 - Access MWS to automate your business today. Link = authorising a third party MWS Developer
2 - Are you a software developer building applications using MWS?. Link = apply for access here .

Please do not copy and paste the ‘MWS overview’ instructions again as I am now fully aware of what I Should need to do but for some reason I am unable to do.