The following pop-ups appear many times when you sign-up, login and write to the blockchain. Below are the solutions when the pop-up doesn't appear.
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1.Reload the page
・Using Google Chrome
・Using Safari
2.Enable pop-ups
・Using Google Chrome
・Using Safari
3.Enable cookies
・Using Google Chrome
・Using Safari
1.Reload the page
・Using Google Chrome
Click on the refresh icon at the top left of your browser.
・Using Safari
Click on the refresh icon at the top center of the screen.
2.Enable pop-ups
If popups do not appear after reloading the page several times, the pop-up is presumably disabled in your browser settings. The following are instructions on how to enable pop-ups.
・Using Google Chrome
1.Click on the “︙” icon in the upper right corner of the browser and select "Settings" button. 
2.Click on "Privacy and security" > "Site settings.”
3.Scroll down to "Content" > Click on "Pop-up and redirects”
4. Click on the icon next to “Blocked (recommended)” to change it to “Allowed.”
・Using Safari.
1.Click on "Safari" in the menu bar and select "Preferences".
2.Click on "Websites" > "Pop-up Windows" and select "Block and Notify" or "Allow" from the settings in the bottom right corner (Make sure "Do not open" is not selected).
3.Enable cookies
If the page does not appear after reloading the page several times, it may be that cookies are disabled in your browser settings. The following explains how to enable cookies.
・Using Google Chrome
1.Click on the “︙” icon in the upper right corner of the browser and select "Settings" button.
2.Click on "Privacy and Security" > "Cookies and other site data".
3.Please make sure that "Block all cookies (not recommended)" is not checked. If this is checked, please check either “Block third-party cookies in incognito” or “Allow all cookies” instead. 
・Using Safari
1.Click on "Safari" in the menu bar and select "Preferences".
2.Click on "Privacy" and make sure "Block all cookies" is not checked. If this is checked, please click the check mark so that this will not be checked. 