You can create a "Budgetary" proposal that customers can only view and don't have to accept. Use this if you want to confirm the budget or plan for the project before sending the proposal, with Proposal Acceptance included.
To create a Budgetary proposal:
1/ Go to the Edit view of the proposal.
2/ Click the Settings icon in the top-right corner.
3/ Set the "Client Acceptance" setting in the side panel to "Budgetary."
In the customer view of the proposal, the "Accept" button is not available. Also, the banner at the top informs the customer that the proposal is budgetary.
You can also create a dedicated proposal template for budgetary proposals and apply its settings to proposals you share as budgetary.
Check out this article for more details.