How to remove <missing> from a cell array, possibly replace with blank space

Originally I imported text (mixed numeric and alphabets/strings) from a file as a table data.

Since the amount of text/data in different lines of the file is different, many of the elements in the table are NaN.

Now I want to write certain specific lines of this table to another file, but I don't want NaN to be written, instead just leave blank space there

What I tried:

fin = strcat(path_in,'/test.txt');  %input filename
file_data = readtable(fin) ;    % read data from the file "fin"

bonds_text= (table2cell(file_data(191:end,:)));
bonds_text(cellfun(@isnan,bonds_text,'UniformOutput',false)) = {[]};

When I try to perform the last line operation, which is to remove NaN by a blank space, it gives me the following error:

Function 'subsindex' is not defined for values of class 'cell'.

I am attaching the file from which I am reading the data

Can you please help me fix this error, or is there another better/simpler way of doing this?

Thank you

[Gaurav Kumar]

Apart from the above mentioned method, I had tried the following:

bonds_text= string(table2cell(file_data(191:end,:)));

This converted cell to string, but all the NaN elements get converted to <missing>. Is there a way to replace all these <missing> by simple blank spaces while writing the file

Thanks

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/fillmissing.html

[Gaurav Kumar]

Thank you very much Walter.

I had actually tried doing the same earlier, and it was giving me an error, but now I corrected my mistake there.

bonds_text= fillmissing(bonds_text,'constant',''); % wrong, single quote, not a string

bonds_text= fillmissing(bonds_text,'constant',""); % correct, double quote, a string