no access to earlier Photoshop version.

you can get the current, and 1 previous version via your adobe cc app.

all other previous versions are available via a link from adobe support*. 

some other (eg, cc 2019) previous versions are available via prodesigntools.com, All the New Adobe CC 2019 Direct Download Links, Now Available! | ProDesignTools

*

using a browser that allows popups and cookies, contact adobe support by clicking here, https://helpx.adobe.com/contact.html?rghtup=autoOpen
in the chat field (lower right), type AGENT
be patient, it can take quite a while to reach a human

p.s. if you're contacted by anyone (via email or private message), it's much more likely to be a scammer than an adobe representative. ie, double check for an employee badge if contacted in the forums and look for an adobe.com domain in the email address if you click reply to an email. then check again and be very suspicious. any other method of contacting (or offering to contact you) is almost certainly a scam.

p.p.s you can also use phone (but chat is usually quicker), https://helpx.adobe.com/contact/phone.html

According to this, everything before 2021 MAY have been removed... but, try the links for yourself
https://community.adobe.com/t5/download-install-discussions/older-versions-pre-2020/td-p/13065324