Nobody is going to work for your company for free. Your equity is worthless. Almost all startups fail so you’re asking others to take on your risk. Not being unkind but trying to manage your expectations.
All new equity is worthless. If you persuade someone to buy some it's a little less worthless and if you demonstrate value by generating revenue then it a little bit less worthless again but of say 1000 new companies, 50 may generate revenue and 5 may get investment and 1 might and that's a big might, give you a return on your money. Ultimately you need to pay the software engineer for the risk they take and you can do that in many ways but I'd say unless it's a technical founder who really is a founder with you - i.e, they said to you, hey I've got this great idea but I need help to realise it, then you need hand over money.