https://www.amazon.com/dp/B079K73S9R/ref=cm_sw_r_cp_apa_fabc_Q4VXEYTX6ZY7ZQAVW99C
On amazon. You can find a ton of cute stuff there. I only had it on the german page of amazon though, but I found it on amazon dot com too:
https://www.amazon.com/-/de/dp/B079K73S9R/ref=sr_1_35?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=dress%2Bcosplay&qid=1613458740&sr=8-35&th=1&psc=1