We already have a blue badge for my 4 year old. Applied for it before applying for DLA. Applied via our LC website, it was £10 and covers him until 2027. They didn't ask for proof of or if he gets DLA. I just needed to explain why he needed one (autism, global development delay, with no sense of danger, elopement risk and refusal to walk at times). I provided supporting evidence (EHCP, diagnoses proof and reports from paediatrician). Was processed and approved within 3 weeks of application