附錄 99.3

GRAPHIC

福爾圖納銀礦有限公司 安全類別 持有人賬號 委託書表格-將於 2024 年 6 月 20 日星期四舉行的年度會議和特別會議。本委託書由管理層徵集並代表管理層徵集。 代理注意事項 1.每位持有人都有權指定自己選擇的其他人或公司(不一定是持有人)出席會議或任何休會或 延期,並代表他們行事。如果您想任命除此處印有姓名的管理候選人以外的個人或公司,請在提供的空白處插入您選擇的 代理持有人的姓名(見反面)。 2。如果證券以多個所有者(例如共同所有權、受託人、遺囑執行人等)的名義註冊,則所有註冊者都應簽署該委託書。如果您代表公司或其他個人投票 ,則可能需要提供文件,證明您有權簽署該代理並註明簽名能力。 3。該代理的簽名方式應與代理服務器上顯示的名稱完全相同。 4。如果未在此委託書背面提供的空白處填寫日期,則該日期將被視為管理層郵寄給持有人的日期。 5。該代理所代表的證券將按照持有人的指示進行投票,但是,如果沒有就任何事項做出這樣的指示,並且代理人任命了背面列出的管理層 被提名人,則該代理人將按照管理層的建議進行投票。 6。根據持有人的 指示,在可能需要的任何投票中,將對本代理所代表的證券投贊成票,或不予表決,或視情況對本文所述的每項事項投反對票。如果您已就任何要採取行動的事項指定了選擇,則將對證券進行相應的投票。 7。除非法律禁止,否則本委託書授予對會議通知和管理信息通告中確定的事項的修改或變更的自由裁量權,或可能在會議或任何休會或延期之前 的其他事項。 8。該代理應與管理層提供的隨附文件一起閲讀。 提交的代理必須在 2024 年 6 月 18 日星期二太平洋時間上午 10:00 之前收到。 每週 7 天、每天 24 小時使用電話或互聯網進行投票! 使用電話投票 • 使用按鍵音 電話撥打下面列出的號碼。 1-866-732-VOTE (8683) 免費電話 使用互聯網進行投票 • 訪問以下網站: www.investorvote.com • 智能手機? 掃描二維碼立即投票。 如果您通過電話或互聯網投票,請勿將此代理郵寄回去。 郵寄投票可能是以公司名義持有的證券或代表他人投票的唯一方法。 通過郵寄或互聯網投票是持有人可以指定某人為代理持有人的唯一方法,而不是此 代理背面指定的管理層候選人。您可以選擇上面概述的兩種投票方法之一來對該代理進行投票,而不是郵寄此代理。 要通過電話或互聯網投票,您需要提供下面列出的控制號碼。 控制號碼 ------- 摺疊 ------- 摺疊

GRAPHIC

------- Fold ------- Fold Appointment of Proxyholder I/We being holder(s) of securities of Fortuna Silver Mines Inc. (the “Company”) hereby appoint: Jorge Ganoza Durant, CEO, or failing him, David Laing, Chairman, or failing him, Linda Desaulniers, Corporate Counsel, or failing her, Sally Whittall, Corporate Secretary (the "Management Nominees") OR Print the name of the person you are appointing if this person is someone other than the Management Nominees listed herein. as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the holder in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual and Special Meeting of shareholders of the Company to be held in the Cheakamus Room, Fairmont Waterfront Hotel, 900 Canada Place, Vancouver, British Columbia on Thursday, June 20, 2024 at 10:00 am, Pacific Time and at any adjournment or postponement thereof. VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES. 1. Number of Directors To set the number of Directors at eight (8). For Against 2. Election of Directors 01. Jorge Ganoza Durant For Withhold 02. Mario Szotlender For Withhold 03. David Farrell For Withhold 04. David Laing 05. Alfredo Sillau 06. Kylie Dickson 07. Kate Harcourt 08. Salma Seetaroo 3. Appointment of Auditors Appointment of KPMG LLP as Auditors of the Company for the ensuing year and authorizing the Directors to fix their remuneration. For Withhold 4. Approval of Change of Name of the Company To consider, and if thought fit, pass a special resolution to approve a change in the name of the Company from “Fortuna Silver Mines Inc.” to “Fortuna Mining Corp.”. For Against Signature of Proxyholder I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, this Proxy will be voted as recommended by Management. Signature(s) Date Interim Financial Statements - Mark this box if you would like to receive Interim Financial Statements and accompanying Management’s Discussion and Analysis by mail. Annual Financial Statements - Mark this box if you would like to receive the Annual Financial Statements and accompanying Management’s Discussion and Analysis by mail. If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail at www.computershare.com/mailinglist. F S V Q 3 6 4 0 0 1 A R 1