What you can suggest
When a designer shares a product with you, they decide what you're allowed to suggest changes to. This isn't something you configure yourself, it's set on their side, and it can be different from one project to the next.
Depending on what they've turned on for you, you might be able to:
Suggest pricing: lead time, RRP, trade price, trade discount and shipping costs
Suggest product details: product name, images, link and specifications
Suggest quantities: quantities on any shared product
Suggest new products: alternatives or additions to what they've shared with you
You can check your permissions for a project at any time - click Project permissions in the top corner of the Overview page for a read-only summary of what's currently on and off, set by the studio.
What it looks like when something isn't turned on
Rather than hiding an action you don't have access to, Programa shows it as disabled. For example, if Suggest new products isn't turned on for you, the Add product button on the Add your quote screen is greyed out, with a note that you don't have permission to add new products.
So if a button or field looks locked while you're quoting, it's not a bug, it just means that particular permission hasn't been extended to you on this project. If you think you need it, the quickest path is asking the designer directly rather than looking for a setting on your end, since there isn't one.
What files you can see
The same panel also controls which project files you have access to - drawings, moodboards, schedules and similar documents. This works a little differently from the suggestion permissions above: rather than showing you a locked or greyed-out version, a file the designer hasn't shared with you simply won't appear in your Project Files tab at all.
If you're expecting to see something and it's not there, it's worth asking the designer directly. As with suggestions, this isn't something you can turn on yourself.
These permissions come into play in Responding to a quote request.