Funders such as UKRI, Wellcome or NIHR require that you apply a Rights Retention statement and a CC BY (Creative Commons Attribution) licence to your submitted manuscript. This ensures that your Author Accepted Manusucript can be made freely available, without embargo in an Institutional Repository irrespective of embargo periods by publishers.
The exact wording differs depending on your funder so make sure you check your own funder's Open Access Policy before you submit your manuscript for publication.
Preprints are a way of getting your journal articles in the public domain before they are published. They are usually uploaded to a preprint server before or at the same time as being submitted for publication. Some funding bodies are now advocating the use or preprints.