These publishers require that you transfer copyright to them. You're allowed to use your own work as part of your work, such as teaching, and sharing it with fe

These publishers require that you transfer copyright to them. You're allowed to use your own work as part of your work, such as teaching, and sharing it with fellow researchers. But you're not allowed to upload the published version of the work elsewhere. Preprints are often allowed, such as on arxiv, are usually allowed.