Wordpress site: Form pre-population

Intro
- We own and rent out self storage to customers in Australia.
- Our website allows users to book self storage units online.
- Users do so on our "Rent Storage Unit Online" web page: https://storagelord.com.au/rent-storage-unit-online/

Current Integration
- We use self-storage management software (SAAS) called 6Storage.
- 6Storage provides a wordpress plugin that integrates the online booking system with our 6Storage property management software.
- The plugin integration works through the 6Storage API - https://developer.6storage.com/

Problem
- The very first form input for the online booking page is to ‘Choose Your Location’
- In many instances, this first form input is redundant, because a User has clicked through to the online booking page from a specific ‘Location’ page
- The user is, in effect, having to re-select a ‘Location’ and hence leads to lower than ideal form completion conversions

Solution
- We would like a solution where the first form input, “Choose your Location”, is prepopulated based on the referring URL.
- For example, if a customer clicks through to renting a unit online (https://storagelord.com.au/rent-storage-unit-online/) from the “Adelaide Storage Units” webpage (https://storagelord.com.au/locations/adelaide-storage/) then the form will have the “Adelaide” location pre-populated
- The ideal solution will be URL based, https://www.laserfiche.com/ecmblog/tech-tip-using-url-parameters-to-pre-fill-form-fields/
- The ideal solution will not require customisation of the 6Storage plugin