People donate to charity for 1 reason above all others.
They are asked to Donate
It is really that simple. Every charity has to ask and solicit donations from their members, supports, and community. How they go about doing that depends on the specific nonprofit. But you have to be willing to ask people to partner with your organization financially.
Now, if they do donate it is because there is also a connection. It could be a connection to you, to your mission/cause, or out of social pressure. People give money to charity for a wide variety of reasons. Though a specific charity would likely have some trends in the motivations of their donor base.
But to circle back around… no one writes a check without being asked. It can be terrifying to ask, but you must. It allows people to say yes or no, and for you to continue in your fundraising towards your goal.