I would contact your local authority to enquire. It seems likely it will be them that ultimately makes any decision about whether and where these signs may be located.
If you think you have an appropriate location for one, you could put the case for that. You may be able to use information from the Big Hedgehog Map to support your case. https://bighedgehogmap.org/
You may need to take into account other road safety issues, whether there is a suitable location to site a sign. How many other signs are in the area (I believe they like to keep numbers of signs down), etc. You may be able to enlist the support of your local M.P. or Councillor.