Go to abcdpdf.com and click the PDF Editor button to open the online PDF editor.

Click Upload or drag and drop your PDF file to the file zone in Online PDF Editor.

Once the file is uploaded, click the "Edit" button, and wait for a moment, then enter the editing page.

In the editor header toolbar to the far left, click the "Signature" icon.

In the pop-up "Add Signature" window, you can select three types of signature: text signature, image signature, and graphical signature. You can choose the appropriate method to set up your signature

After adjusting, click the "OK" button and your signature will appear in the current page and follow your mouse. You can click in the appropriate position to place your signature. You can adjust the size of the signature, and then move it to the appropriate position.

When you are satisfied with the signature, click the "Done" button in the lower right corner of the page to save your modifications.

After saving, you will be automatically redirected to the download page. Click the "Download" button in the middle of the page to download your document.